1 Methods for investigating reaction rates includeA colorimetryB measurement of change in volumeC measurement of change of massD quenching followed by titrating with acid

2 Which method would be most suitable to investigate the rate of the following reactions

(a) HCOOCH3(aq) + NaOH(aq) 1048687 HCOONa(aq) + CH3OH(aq)

ABCD

(b) (CH3)2C=CH2(g) + HI(g) 10486871048687 (CH3)3CI(g))ABCD

(c) BrO3ndash(aq) + 5Brndash(aq) + 6H+(aq) 1048687 3Br2(aq) + 3H2O(l)

ABCD

3 2H2(g) + 2NO(g) 1048687 2H2O(g) + N2(g)This reaction is first order with respect to hydrogen and second order with respect tonitrogen(II) oxideBy what factor will the initial rate increase if the concentration of hydrogen andnitrogen(II) oxide are both tripledA 3B 9C 12D 27

4 What are the units of Kc for the following equilibrium 2SO2(g) + O2(g) 1048687 2SO3(g)A atmB atmndash1

C dm3 molndash1

D mol dmndash3

5 The graph below shows the yield of product in a gaseous equilibrium at different

temperatures and pressuresThe forward reaction in the equilibrium is

A exothermic and the number of moles of gas is increasingB endothermic and the number of moles of gas is increasingC exothermic and the number of moles of gas is decreasingD endothermic and the number of moles of gas is decreasing

6 Which of the following is not a reaction of a BrOslashnsted-Lowry acid and base

A CH3Cl + OHndash 1048687 CH3OH + ClndashB NH3 + HCl 104868710486871048687NH4+ + ClndashC H2O + HSO4ndash 1048687 H2SO4 + OHndash

D HCO3ndash + H2O 1048687 CO32ndash + H3O+

7 A buffer solution is made from ammonia and ammonium chloride When a small

amount of acid is added to this bufferA hydrogen ions in the acid combine with chloride ions to make HClB hydrogen ions in the acid combine with NH3 to make NH4+C NH4+ ions dissociate to make more NH3D the hydrogen ions in the acid prevent dissociation of the NH4Cl

8 Information about four samples of acid is shown belowSample 1 10 mol dmndash3 HClSample 2 10 mol dmndash3 H2SO4

Sample 3 01 mol dmndash3 HClSample 4 01 mol dmndash3 CH3COOHWhich of the following lists shows the samples in order of increasing pH

A 1 2 3 4B 4 3 2 1C 2 1 3 4D 4 3 1 2

9(a)Calculate the pH of 025 mol dmndash3 hydrochloric acid

(b) Propanoic acid CH3CH2COOH is a weak acid with Ka = 13 1048687 10ndash5 mol dmndash3

at 251048687C(i) Write the expression for Ka for propanoic acid

(ii) Calculate the pH of 025 mol dmndash3 propanoic acid at 251048687C

(c) During a titration 10 cm3 010 mol dmndash3 sodium hydroxide was added to 10 cm3

of 025 mol dmndash3 propanoic acid(i) Write an equation for the reaction which occurs State symbols are not required

(ii) At this point the titration mixture contains 15 1048687 10ndash3 moles of propanoic acidand 10 1048687 10ndash3 moles of propanoate ion

Use your expression for Ka for propanoic acid to calculate the pH of the mixture

(iii) When a further small amount of 010 mol dmndash3 sodium hydroxide is added inthe titration the pH changes very little Explain why the pH change is small

(iv) Draw the titration curve showing the change in pH when 010 mol dmndash3

sodiumhydroxide is added to 10 cm3 of 025 mol dmndash3 propanoic acid until present inexcess The equivalence point is 25 cm3

(v) Explain referring to your data booklet whether bromocresol green would be asuitable indicator for this titration

10 A student investigated the reaction between iodine and propanone in acidic conditions

CH3COCH3(aq) + I2(aq) 1048687 CH3COCH2I(aq) + HI(aq) 50 cm3 of 0020 mol dmndash3 iodine solution was measured into a flask 25 cm3 of propanone and 25 cm3 of 10 mol dmndash3 sulfuric acid were

measured into a second flask Several 10 cm3 samples of 05 mol dmndash3 sodium hydrogencarbonate

solution were placed in separate conical flasks The mixture of propanone and sulfuric acid was added to the iodine

and a clock started At two minute intervals 10 cm3 of the reaction mixture was removed

and added to one of the flasks containing sodium hydrogencarbonate solution

The contents of this flask were then titrated with 001 mol dmndash3 sodium thiosulfate

(a) Explain the purpose of adding the reaction mixture to the sodium hydrogencarbonate

(b) What indicator should be used in the titration

(c) In this experiment the concentration of the iodine was 0020 mol dmndash3

and theconcentrations of propanone and sulfuric acid were both 100 mol dmndash3 Why wasthe iodine solution used much less concentrated than the propanone and sulfuricacid

(d) The shape of the graph obtained from the results of the experiment is shown below

Use the graph to deduce the order of reaction with respect to iodine explaining yourreasoning

(e) The solutions used in this experiment could be measured using either measuringcylinders or pipettesGive one advantage of using a measuring cylinder and one advantage of using apipette

(f) In a further investigation different volumes of sulfuric acid propanone iodine andwater were mixed The time taken for the mixture to go colourless was measuredThe experiments were repeated and the results below show average values for the

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

5 The graph below shows the yield of product in a gaseous equilibrium at different

temperatures and pressuresThe forward reaction in the equilibrium is

A exothermic and the number of moles of gas is increasingB endothermic and the number of moles of gas is increasingC exothermic and the number of moles of gas is decreasingD endothermic and the number of moles of gas is decreasing

6 Which of the following is not a reaction of a BrOslashnsted-Lowry acid and base

A CH3Cl + OHndash 1048687 CH3OH + ClndashB NH3 + HCl 104868710486871048687NH4+ + ClndashC H2O + HSO4ndash 1048687 H2SO4 + OHndash

D HCO3ndash + H2O 1048687 CO32ndash + H3O+

7 A buffer solution is made from ammonia and ammonium chloride When a small

amount of acid is added to this bufferA hydrogen ions in the acid combine with chloride ions to make HClB hydrogen ions in the acid combine with NH3 to make NH4+C NH4+ ions dissociate to make more NH3D the hydrogen ions in the acid prevent dissociation of the NH4Cl

8 Information about four samples of acid is shown belowSample 1 10 mol dmndash3 HClSample 2 10 mol dmndash3 H2SO4

Sample 3 01 mol dmndash3 HClSample 4 01 mol dmndash3 CH3COOHWhich of the following lists shows the samples in order of increasing pH

A 1 2 3 4B 4 3 2 1C 2 1 3 4D 4 3 1 2

9(a)Calculate the pH of 025 mol dmndash3 hydrochloric acid

(b) Propanoic acid CH3CH2COOH is a weak acid with Ka = 13 1048687 10ndash5 mol dmndash3

at 251048687C(i) Write the expression for Ka for propanoic acid

(ii) Calculate the pH of 025 mol dmndash3 propanoic acid at 251048687C

(c) During a titration 10 cm3 010 mol dmndash3 sodium hydroxide was added to 10 cm3

of 025 mol dmndash3 propanoic acid(i) Write an equation for the reaction which occurs State symbols are not required

(ii) At this point the titration mixture contains 15 1048687 10ndash3 moles of propanoic acidand 10 1048687 10ndash3 moles of propanoate ion

Use your expression for Ka for propanoic acid to calculate the pH of the mixture

(iii) When a further small amount of 010 mol dmndash3 sodium hydroxide is added inthe titration the pH changes very little Explain why the pH change is small

(iv) Draw the titration curve showing the change in pH when 010 mol dmndash3

sodiumhydroxide is added to 10 cm3 of 025 mol dmndash3 propanoic acid until present inexcess The equivalence point is 25 cm3

(v) Explain referring to your data booklet whether bromocresol green would be asuitable indicator for this titration

10 A student investigated the reaction between iodine and propanone in acidic conditions

CH3COCH3(aq) + I2(aq) 1048687 CH3COCH2I(aq) + HI(aq) 50 cm3 of 0020 mol dmndash3 iodine solution was measured into a flask 25 cm3 of propanone and 25 cm3 of 10 mol dmndash3 sulfuric acid were

measured into a second flask Several 10 cm3 samples of 05 mol dmndash3 sodium hydrogencarbonate

solution were placed in separate conical flasks The mixture of propanone and sulfuric acid was added to the iodine

and a clock started At two minute intervals 10 cm3 of the reaction mixture was removed

and added to one of the flasks containing sodium hydrogencarbonate solution

The contents of this flask were then titrated with 001 mol dmndash3 sodium thiosulfate

(a) Explain the purpose of adding the reaction mixture to the sodium hydrogencarbonate

(b) What indicator should be used in the titration

(c) In this experiment the concentration of the iodine was 0020 mol dmndash3

and theconcentrations of propanone and sulfuric acid were both 100 mol dmndash3 Why wasthe iodine solution used much less concentrated than the propanone and sulfuricacid

(d) The shape of the graph obtained from the results of the experiment is shown below

Use the graph to deduce the order of reaction with respect to iodine explaining yourreasoning

(e) The solutions used in this experiment could be measured using either measuringcylinders or pipettesGive one advantage of using a measuring cylinder and one advantage of using apipette

(f) In a further investigation different volumes of sulfuric acid propanone iodine andwater were mixed The time taken for the mixture to go colourless was measuredThe experiments were repeated and the results below show average values for the

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

A 1 2 3 4B 4 3 2 1C 2 1 3 4D 4 3 1 2

9(a)Calculate the pH of 025 mol dmndash3 hydrochloric acid

(b) Propanoic acid CH3CH2COOH is a weak acid with Ka = 13 1048687 10ndash5 mol dmndash3

at 251048687C(i) Write the expression for Ka for propanoic acid

(ii) Calculate the pH of 025 mol dmndash3 propanoic acid at 251048687C

(c) During a titration 10 cm3 010 mol dmndash3 sodium hydroxide was added to 10 cm3

of 025 mol dmndash3 propanoic acid(i) Write an equation for the reaction which occurs State symbols are not required

(ii) At this point the titration mixture contains 15 1048687 10ndash3 moles of propanoic acidand 10 1048687 10ndash3 moles of propanoate ion

Use your expression for Ka for propanoic acid to calculate the pH of the mixture

(iii) When a further small amount of 010 mol dmndash3 sodium hydroxide is added inthe titration the pH changes very little Explain why the pH change is small

(iv) Draw the titration curve showing the change in pH when 010 mol dmndash3

sodiumhydroxide is added to 10 cm3 of 025 mol dmndash3 propanoic acid until present inexcess The equivalence point is 25 cm3

(v) Explain referring to your data booklet whether bromocresol green would be asuitable indicator for this titration

10 A student investigated the reaction between iodine and propanone in acidic conditions

CH3COCH3(aq) + I2(aq) 1048687 CH3COCH2I(aq) + HI(aq) 50 cm3 of 0020 mol dmndash3 iodine solution was measured into a flask 25 cm3 of propanone and 25 cm3 of 10 mol dmndash3 sulfuric acid were

measured into a second flask Several 10 cm3 samples of 05 mol dmndash3 sodium hydrogencarbonate

solution were placed in separate conical flasks The mixture of propanone and sulfuric acid was added to the iodine

and a clock started At two minute intervals 10 cm3 of the reaction mixture was removed

and added to one of the flasks containing sodium hydrogencarbonate solution

The contents of this flask were then titrated with 001 mol dmndash3 sodium thiosulfate

(a) Explain the purpose of adding the reaction mixture to the sodium hydrogencarbonate

(b) What indicator should be used in the titration

(c) In this experiment the concentration of the iodine was 0020 mol dmndash3

and theconcentrations of propanone and sulfuric acid were both 100 mol dmndash3 Why wasthe iodine solution used much less concentrated than the propanone and sulfuricacid

(d) The shape of the graph obtained from the results of the experiment is shown below

Use the graph to deduce the order of reaction with respect to iodine explaining yourreasoning

(e) The solutions used in this experiment could be measured using either measuringcylinders or pipettesGive one advantage of using a measuring cylinder and one advantage of using apipette

(f) In a further investigation different volumes of sulfuric acid propanone iodine andwater were mixed The time taken for the mixture to go colourless was measuredThe experiments were repeated and the results below show average values for the

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

Use your expression for Ka for propanoic acid to calculate the pH of the mixture

(iii) When a further small amount of 010 mol dmndash3 sodium hydroxide is added inthe titration the pH changes very little Explain why the pH change is small

(iv) Draw the titration curve showing the change in pH when 010 mol dmndash3

sodiumhydroxide is added to 10 cm3 of 025 mol dmndash3 propanoic acid until present inexcess The equivalence point is 25 cm3

(v) Explain referring to your data booklet whether bromocresol green would be asuitable indicator for this titration

10 A student investigated the reaction between iodine and propanone in acidic conditions

CH3COCH3(aq) + I2(aq) 1048687 CH3COCH2I(aq) + HI(aq) 50 cm3 of 0020 mol dmndash3 iodine solution was measured into a flask 25 cm3 of propanone and 25 cm3 of 10 mol dmndash3 sulfuric acid were

measured into a second flask Several 10 cm3 samples of 05 mol dmndash3 sodium hydrogencarbonate

solution were placed in separate conical flasks The mixture of propanone and sulfuric acid was added to the iodine

and a clock started At two minute intervals 10 cm3 of the reaction mixture was removed

and added to one of the flasks containing sodium hydrogencarbonate solution

The contents of this flask were then titrated with 001 mol dmndash3 sodium thiosulfate

(a) Explain the purpose of adding the reaction mixture to the sodium hydrogencarbonate

(b) What indicator should be used in the titration

(c) In this experiment the concentration of the iodine was 0020 mol dmndash3

and theconcentrations of propanone and sulfuric acid were both 100 mol dmndash3 Why wasthe iodine solution used much less concentrated than the propanone and sulfuricacid

(d) The shape of the graph obtained from the results of the experiment is shown below

Use the graph to deduce the order of reaction with respect to iodine explaining yourreasoning

(e) The solutions used in this experiment could be measured using either measuringcylinders or pipettesGive one advantage of using a measuring cylinder and one advantage of using apipette

(f) In a further investigation different volumes of sulfuric acid propanone iodine andwater were mixed The time taken for the mixture to go colourless was measuredThe experiments were repeated and the results below show average values for the

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(v) Explain referring to your data booklet whether bromocresol green would be asuitable indicator for this titration

10 A student investigated the reaction between iodine and propanone in acidic conditions

CH3COCH3(aq) + I2(aq) 1048687 CH3COCH2I(aq) + HI(aq) 50 cm3 of 0020 mol dmndash3 iodine solution was measured into a flask 25 cm3 of propanone and 25 cm3 of 10 mol dmndash3 sulfuric acid were

measured into a second flask Several 10 cm3 samples of 05 mol dmndash3 sodium hydrogencarbonate

solution were placed in separate conical flasks The mixture of propanone and sulfuric acid was added to the iodine

and a clock started At two minute intervals 10 cm3 of the reaction mixture was removed

and added to one of the flasks containing sodium hydrogencarbonate solution

The contents of this flask were then titrated with 001 mol dmndash3 sodium thiosulfate

(a) Explain the purpose of adding the reaction mixture to the sodium hydrogencarbonate

(b) What indicator should be used in the titration

(c) In this experiment the concentration of the iodine was 0020 mol dmndash3

and theconcentrations of propanone and sulfuric acid were both 100 mol dmndash3 Why wasthe iodine solution used much less concentrated than the propanone and sulfuricacid

(d) The shape of the graph obtained from the results of the experiment is shown below

Use the graph to deduce the order of reaction with respect to iodine explaining yourreasoning

(e) The solutions used in this experiment could be measured using either measuringcylinders or pipettesGive one advantage of using a measuring cylinder and one advantage of using apipette

(f) In a further investigation different volumes of sulfuric acid propanone iodine andwater were mixed The time taken for the mixture to go colourless was measuredThe experiments were repeated and the results below show average values for the

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(b) What indicator should be used in the titration

(c) In this experiment the concentration of the iodine was 0020 mol dmndash3

and theconcentrations of propanone and sulfuric acid were both 100 mol dmndash3 Why wasthe iodine solution used much less concentrated than the propanone and sulfuricacid

(d) The shape of the graph obtained from the results of the experiment is shown below

Use the graph to deduce the order of reaction with respect to iodine explaining yourreasoning

(e) The solutions used in this experiment could be measured using either measuringcylinders or pipettesGive one advantage of using a measuring cylinder and one advantage of using apipette

(f) In a further investigation different volumes of sulfuric acid propanone iodine andwater were mixed The time taken for the mixture to go colourless was measuredThe experiments were repeated and the results below show average values for the

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

Use the graph to deduce the order of reaction with respect to iodine explaining yourreasoning

(e) The solutions used in this experiment could be measured using either measuringcylinders or pipettesGive one advantage of using a measuring cylinder and one advantage of using apipette

(f) In a further investigation different volumes of sulfuric acid propanone iodine andwater were mixed The time taken for the mixture to go colourless was measuredThe experiments were repeated and the results below show average values for the

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(i) Explain why water is added in experiments 2 and 3

(ii) Show how you would use the data in the table to deduce the order of reactionwith respect to propanone and hydrogen ions Write the rate equation for thereaction

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

11 The reaction between carbon monoxide and hydrogen reaches a dynamic equilibrium

CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Which of these statements about a dynamic equilibrium is not true

A The forward rate of reaction is equal to the backward rate of reactionB The concentrations of the products and reactants do not changeC The concentrations of the products and reactants are equalD The equilibrium can be approached from either direction

(b) The Kc expression for the above reaction is

12 Hydrogen and iodine both with an initial concentration of 0010 mol dm10486871048687

were allowed to react At equilibrium the concentration of hydrogen iodide was00030 mol dm H2(g) + I2(g) 1048687 2HI(g)Kc is calculated using the values

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

The reaction below reached a dynamic equilibrium from an initial mixture of all foursubstances P Q R and S in aqueous solution P + Q 1048687 R + SThe following data were obtained

13 Kc for the equilibrium isA 010B 033C 300D 100

14 The Haber process is used to make ammonia from nitrogen and hydrogen at 450 1048687C

N2(g) + 3H2(g) (a) If the partial pressures of these gases were measured in atm the units of theequilibrium constant Kp will beA atmB atmC atmD atm(b) When the temperature of the system is increasedA Kp decreasesB Kp increasesC Kp stays the sameD Kp first decreases and then increases

15 In high performance liquid chromatography HPLC which of these factors does not

affect the time taken for a component to pass through the columnA Type of detectorB Material of stationary phaseC Particle size of stationary phaseD Temperature of column

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

16 When equimolar amounts of the solutions below are mixed which forms a buffer

solution with a pH less than 7A Hydrochloric acid and sodium chlorideB Ethanoic acid and sodium ethanoateC Sodium hydroxide and sodium chlorideD Ammonia and ammonium chloride

17 The pH of a 15 mol dmndash3 solution of hydrochloric acid HCl(aq) isA B C 018D 150

18 The exothermic reaction between carbon monoxide and hydrogen can be used

industrially to make methanol The process is carried out at 250 1048687C and between 50 and 100 atm CO(g) + 2H2(g) 1048687 CH3OH(g)(a) Explain why increasing the pressure increases the yield of methanol Give onedisadvantage of increasing the pressure

(b) The reaction gives a greater equilibrium yield at 100 1048687C than at 250 1048687C(i) Explain in terms of the entropy change of the surroundings and the totalentropy change of the reaction why this is soA calculation is not required

(ii) Explain why the reaction is nevertheless carried out at 250 1048687C

(c) Given that the reaction is an equilibrium suggest two ways in which the atom

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

economy of this process could be maximised without changing the temperature orpressure

19 This question is about the kinetics of the reaction between bromoethane and aqueous

hydroxide ions(a) The results of an experiment to find the initial rate of the reaction are shown in thetable below

The rate equation for the reaction is rate = k[CH3CH2Br][OH1048687] (i) Calculate the value of k Give your answer to three significant figures andinclude units

(ii) Calculate the initial rate if the concentrations of both reactants were changed to0020 mol dm10486871048687

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(b) (i) State the order of the reaction

(ii) The mechanism for this reaction can be inferred from the rate equation Drawthe transition state formed in the reaction between bromoethane and hydroxideions

(c) The rate constant for the reaction between bromoethane and hydroxide ions wasdetermined at five different temperatures The results are shown in the table below

(i) Complete the missing values in the table

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(ii) Plot a graph of ln k against 1T Calculate the gradient of your graph and usethis to calculate the activation energy EA The Arrhenius equation can beexpressed as

20 The bubble bath lsquoColour Change Mateyrsquo has amongst its ingredients the weak acid

benzoic acid as well as the indicator bromocresol green When it is added to bathwater its colour changes from yellow to blue

(a) (i) Write the Ka expression for the dissociation of benzoic acid C6H5COOH

(ii) Use the data on page 18 of the data booklet to calculate the pH of a solution ofbenzoic acid C6H5COOH of concentration 00025 mol dm

why the bubble bath changes colour when it is diluted by being added to the bath

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

water

21 Which of the following methods would not be suitable for measuring the rate of the

reaction between methanoic acid and bromine HCOOH(aq) + Br2(aq) 1048687 2H+(aq) + 2Br1048687(aq) + CO2(g)A ColorimetryB Measuring change in electrical conductivityC Quenching samples and titrating with acidD Measuring change in pressure

22 The equation below shows the hydrolysis of a bromoalkane RBr + OH1048687 1048687 ROH + Br1048687For a particular bromoalkane the rate equation is rate = k[RBr]The bromoalkane RBr is most likely to beA CH3BrB CH3CH2BrC (CH3)3CCH2BrD (CH3)3CBr

23 Methanol is produced in the equilibrium reaction 2H2(g) + CO(g) 1048687 CH3OH(g) 1048687H = 1048687183 kJ mol10486871

Addition of more hydrogen to the equilibrium mixture at constant temperatureA increases the equilibrium yield of methanolB decreases the equilibrium yield of methanolC increases the value of KpD decreases the value of Kp

24 The equation for the equilibrium between NO2(g) and N2O4(g) can be written in two ways

2NO2(g) 1048687 N2O4(g) Equilibrium constant = Kc

or NO2(g) 1048687 frac12N2O4(g) Equilibrium constant = KcWhich expression is correctA Kc = KcB Kc = (Kc)2

C Kc = 2(Kc)D Kc = frac12Kc

25 40 mol of methanoic acid are reacted with 60 mol of ethanolHCOOH(l) + C2H5OH(l) 1048687 HCOOC2H5(l) + H2O(l)The equilibrium mixture contains 30 mol of HCOOC2H5The equilibrium constant Kc for the reaction is

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

A 033B 10C 30D 40

26 A solution of hydrochloric acid has pH 30 When it is made 10 times more dilute the pH is

A 03B 20C 40D 130

27 The titration curves below were obtained using different acids and bases each with concentration 01 mol dmndash3

(a) Which curve is produced by adding ammonia to 25 cm3 of hydrochloric acid

ABC

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

D(b) Which curve is produced by adding ethanoic acid to 25 cm3 of sodium hydroxide

ABCD(c) An indicator with pKIn 85 is suitable for the following titrations

A Titrations A and B onlyB Titrations A B and D onlyC Titration C onlyD Titrations A B C and D

28 Nitrogen(IV) oxide NO2 is a brown gas which is a pollutant in air It is produced in the reaction below

2NO(g) + O2(g) 1048687 2NO2(g)(a) The table below shows the results of a series of experiments to measure the rate ofthis reaction at 298 K

(i) State with reasons the order of reaction with respect to oxygen and the order ofreaction with respect to nitrogen(II) oxide NO

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(ii) Write the rate equation for the reaction

(iii) Calculate the value of the rate constant Include units in your answer

(b) Nitrogen(IV) oxide in air reacts with carbon monoxide in car exhausts Thefollowing two-step reaction mechanism has been suggestedStep 1 2NO2(g) 1048687 NO(g) + NO3(g) SlowStep 2 NO3(g) + 2CO(g) 1048687 NO(g) + 2CO2(g) Fast(i) Write the equation for the overall reaction which takes place

(ii) The overall reaction is second order Suggest a rate equation for this reactionjustifying your answer

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

29 Methanoic acid ethanoic acid and iodic(I) acid HIO are all weak acids

(a) The values of the acid dissociation constant Ka for methanoic and ethanoic acidat 298 K are given below Iodic(I) acid has a pKa of 1064 Complete the table bycalculating the value of Ka for iodic(I) acid

(b) (i) Write the expression for Ka for methanoic acid HCOOH

(ii) Calculate the pH of a solution of methanoic acid with concentration050 mol dmndash3 at 298 K

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(iii) State one of the assumptions you have made when calculating the pH in (ii)

(c) The following equilibrium occurs in a mixture of pure methanoic and ethanoic acidsHCOOH + CH3COOH 1048687 HCOOndash + CH3COOH2+

(i) Give the formulae of the two BrOslashnsted-Lowry acids in this equilibrium (ii) Write an equation showing the products of the equilibrium which is set up wheniodic(I) acid is mixed with ethanoic acid

HIO + CH3COOH +

(d) A shampoo is buffered by the addition of a mixture of methanoic acid and sodiummethanoateThe pH of this shampoo is 49 Calculate the hydrogen ion concentration in theshampoo and hence the ratio of methanoate ions to methanoic acid

Consider the equilibrium below CO(g) + Cl2(g) _ COCl2(g)(a) An increase in pressure by a factor of 2 willA quadruple KpB double KpC have no effect on KpD halve Kp

(b) The units of Kp areA atm__

B atm__

C atmD atm2

Which of these will not improve the overall yield of the Haber process

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

A Increasing the pressureB Liquefying then removing the ammonia from the reactionC Increasing the temperatureD Recycling unreacted nitrogen and hydrogen

In which of these reactions is the hydrogensulfate ion HSO4_ behaving as a Broslashnsted-Lowry base

10 The rate equation for the reaction between hydrogen gas and nitrogen monoxide gas is rate = k[NO]2[H2]If the concentration of both reactants is doubled the rate will increase by a factor ofA 3B 4C 6D 8

A reaction has the rate equation rate = k[X][Y]2[Z] The concentrations of each reactantare shown in the table belowReactant Concentration mol dm__

the numerical value of k is

(b) The units for the rate constant k are

(b) The units for the rate constant k are