ــ14 arab republic of egypt لوأ / ج.ع.ث ح 14 2...

/ أول ج.ث.ع {266}

ح 14 ــ 2ــ

ةثانيال بقية األسئلة فى الصفحة

الثالثةبقية األسئلة فى الصفحة

ح 14

/ ج.ث.ع {266} ع ـتاب

أول خ

ريـالتا

التوقيــــــــع

ســـــمال

ا

خري

التا


ســـــمال

ا ا

ى ويل اليدو

صأل

ق لطاب

جع ومرو

ــطب

جنة الفنية ،سئولية الل

ى معل

ع

ARAB REPUBLIC OF EGYPT Ministry of Education

General Secondary Education Certificate Examination, 2014 { First Session – New System }

Chemistry Time: 3 Hours

{ Write all the chemical equations balanced, mention the conditions of the reaction }

{باللغة اإلنجليزية } الكيميـــاء

} أربع صفحاتاألسئلة فى } ـ يسلم الطالب ورقة امتحانيه باللغة العربية مع الورقة الـمترجمة .1: تنبيه مهم

. اإلجابات المتكررة عن أسئلة االختيار من متعدد لن تقدر ويتم تقدير اإلجابة األولى فقطـ 2

Second:

1- What is the chemical name for each of the following…?

a ) Gas of swamps. b ) Gamexane.

2- Mention the second Faraday’s law, and show how to achieve it practically.

3- Illustrate by balanced chemical equations how to obtain:

a ) Benzene from phenol and vice versa.

b ) T.N.T (tri nitro toluene) from sodium benzoate.

Question (2) ( 15 marks )

First: Write the scientific expression which illustrate each of the following

statements:

1- The result of multiplying electric current intensity in ampere by a unit time

in second.

2- The electrode at which the oxidation process takes place in electrochemical

cells.

3- Apparently a stationary system but in reality it is a dynamic system.

4- The minimum amount of energy must be gained by a molecule to react at

collision.

5- The volume of gases involved in a reaction, and the gases produced are exist

in a fixed ratio.

6- The reactions which are used for determination of substances that form

sparingly soluble products.

Second:

1- Which of the following compounds have molecular isomers…?

a ) Methyl acetate (CH3COOCH3) b ) Phenyl acetate (CH3COOC6H5)

c )Methyl salicylate d ) Methyl benzoate

e ) Ethyl benzoate (C6H5COOC2H5) f ) Ethyl formate (HCOOC2H5)

2- What is meant by volatilization method in quantitative analysis?

3- Compare between each of the following:

a ) Complete and reversible reactions.

b ) Neutralization and hydrolysis.

c ) Primary cells and secondary cells.

OH

O

C O CH3 COOCH3

Answer four questions only from the following


First: Choose the correct answer for each of the following :

1- 300 mole of CH3COOH molecules contain …….. carbon atom.

a ) 600 b ) 450 c ) 300 d ) 150

2- Strong electrolyte solution is a completely ……..

a ) Reacted b ) decomposed c ) dissolved d ) Ionized

3- From the general properties of aqueous acidic solutions……..

a ) Their pH values are more than 7.

b ) Change litmus paper to blue.

c ) Remove the colour of phenolphthalein.

d ) Have a fatty touch.

4- The value of the standard hydrogen electrode is ……..

a ) –1 b ) zero c ) +1 d ) 1.1

5- The number of atoms in 15 gram of formaldehyde ( HCHO ) = ……..

( C = 12 , H = 1 , O = 16 )

a ) Double Avogadro’s number b ) half Avogadro’s number

c ) Three times Avogadro’s number d ) Quarter Avogadro’s number

6- The graph number …….. illustrates the relationship between each of the

forward and the reversible reactions on adding a catalyst to the reaction.

( g ) 3( g ) 2NH 2( g ) + 3 H 2N

a ) b ) c ) d )

Reversible reaction

Forw

ard

rea

ctio

n

Forw

ard

rea

ctio

n

Forw

ard

rea

ctio

n

Forw

ard

rea

ctio

n

Reversible reaction Reversible reaction Reversible reaction

ةرابعبقية األسئلة فى الصفحة ال

انتهت األسئلة

ى ويل اليدو

صأل

ق لطاب

جع ومرو

ــطب

سئولية الى م

علع

جنة الفنية ،ل

/ أول ج.ث.ع {266} ع ـتاب

/ ج.ث.ع {266} ع ـتاب

أول

خريـ

التا


ســـــمال

ا

خري

التا


ســـــمال

ا ا

ح 14 ــ 3ــ

ح 14

ــ 4ــ


First:

1- What is meant by freons? Mention their uses, and their environmental

harmful effect.

2- Write the equations for preparing ethene (ethylene) in laboratory, mention

the condition of the reaction.

Second:

1- " A lead-Acid battery is developed and becomes the suitable kind of

batteries in cars ". Show by drawing with a labeled diagram its structure,

then write the total reaction for the battery.

2- What is the role of the following scientists in chemistry?

a ) Le Chatelier.

b ) Avogadro.

c ) Ostwald.

3- A student prepared two test tubes, she put in the first one a solution of

sodium carbonate and ammonium chloride in the other test tube. She

detected the solution by a blue litmus paper, she found that the paper

retains its blue colour in the first solution and turns red in the second

solution. explain by balanced chemical equations these results.


First:

1- What is meant by…?

a ) Titration.

b ) Indicators.

c ) Ionic equilibrium.

2- " Ethanol is used in many industries such as converted alcohol, perfumes

and alcoholic liquors ".

a ) what are the additives provided to ethanol to become a converted

alcohol? and why they are added?

b ) Illustrate how to detect the taking of drivers for liquors.

3- Illustrate by a practical experiment how to test for carbon and hydrogen

elements in an organic substance.

Second:

1- Explain by an experiment, the effect of dilution on the ionization of 0.1

molar solutions from each of hydrogen chloride and acetic acid.

2- Calculate the hydrogen ion concentration in 0.1 molar acetic acid solution

at 25 c°, provided that the equilibrium constant of the acid is 1.8×10-5

3- Illustrate by drawing the electroplating of a jug by a layer of silver.


First: Write the scientific explanation for each of the following:

1- The density of carbon dioxide gas is more than the density of oxygen gas.

2- Cyclic propane forms a strong burning mixture with air.

3- The amount of ammonia gas which is prepared from nitrogen and hydrogen

gases is increased by increasing pressure.

4- The boiling point of sorbitol is higher than that of glycerol.

5- The synthetic detergents have an important role in removing spots and

dirties from textiles and clothes.

Second:

1- In an electroplating process to plate copper by gold, a 0.5 faraday was

passed through an aqueous solution of gold (III) chloride.

Calculate the volume of the deposited gold layer given that the atomic mass

of gold is 196.98 (a.m.u.) and its density is 13.2 gram/cm3, then write the

chemical reaction taking place at the cathode.

2- Examine the following compound,

then answer the following:

a ) What are the numbers of sigma ( δ ) and pi bonds ( π ) which are

present in vinyl acetylene?

b ) How many moles of hydrogen gas are required to convert this

compound from unsaturated aliphatic hydrocarbon to a saturated one?

c ) Mention the name of the saturated compound produced on adding

hydrogen according to IUPAC system.

3- Mention the chemical equation with drawing the apparatus used for

preparation of acetylene gas in laboratory.

H H

H C C C C H

1

Question one (15 marks)

Firstly : 6 marks (6×1= 6)

1- a ) 600.

2- d ) Ionized.

3- c ) Remove the colour of phenolphthalein.

4- b ) Zero .

5- a ) Double Avogadro’s number.

6- a )

Secondly: 9 marks 1- a ) Gas of swamps : methane gas (CH4) . (p:245) (½ mark)

b ) Gamixane : benzene hexa chloride C6H6Cl6 . (p:269) (½ mark) 2- Faraday's second Law: the masses of the different materials formed or consumed by the

same amount of electricity are proportional to their equivalent masses. (1 mark) To achieve practically this law the same quantity of electricity is passed in different solutions such as (dilute sulphuric acid, copper sulphate, silver chloride), The masses of the formed materials at the cathode in the cells which are hydrogen, copper, and silver respectively are proportional to their equivalent masses in the ratio. p:218 (1 mark)(يكتفى بالشرح أو الرسم فقط)

3- Each equation (1 mark) (6×1=6) a ) Preparation of benzene from phenol: (p: 265, 269, 300)

b ) Tri nitro toluene: (p: 266, 271, 272)

( 06) ىـالدرجة العظم

( 06) الدرجة الصغرى

( 5) اتــدد الصفحـع

[600 ]

الدور األول

) نظام حديث (

جمهورية مصر العربية مـة والتعليـوزارة التربي الدراسة الثانوية العامةامتحان شهادة إتمام م 6624لعام [ الكيمياء باالنجليزيةنموذج إجابة ]

OH

+ ZnO Zn

∆

300 atm.

300° C

OH

+ NaOH + NaCl

Cl

+ NaOH + Na2CO3 CaO

∆

COONa

+ CH3Cl + HCl AlCl3

anhydrous

CH3

+ 3HNO3 + 3H2O H2SO4

CH3

O2N

CH3

NO2

NO2

+ Cl2 + HCl FeCl3

indirct sun light

Cl

2

6624 [ الكيمياء باالنجليزية نموذج إجابة ] / ح أول ث.ع / 600تابع

Question two (15 marks):

Firstly : 6 marks (6×1= 6)

1- Quantity of electricity (p:218)

2- Anode (p:209)

3- Equilibrium system (p:167)

4- Activation energy (p:169)

5- Gay-Lussac's law (p:245)

6- Precipitation reactions (p:152)

Secondly: (9 marks)

1- (2 marks)

Molecular isomers exist between

Phenyl acetate (CH3COOC6H5) (½ mark) and methyl benzoate (C6H5COOCH3) (½ mark)

Ethyl formate (HCOOC2H5) (½ mark) and Methyl acetate (CH3COOCH3) (½ mark)

2- Volatilization method: (1 mark)

This method is based on the volatilization of element or compound to be determined

followed by its measurement either by collecting the volatile material and determining its

mass or by measuring the amount lost from the original mass of the substance. (p:156)

3- 6 marks (3 × 2) = 6

a) Points of comparison Complete reaction (p:167) Reversible reaction(p:168)

Direction of the reaction It proceeds in one direction It proceeds in two directions

products Escape from the system by

precipitate or by evolving

gases ex: reaction between

metal and dilute acid.

(1 mark)

Both the reactants and the

products are present in the

medium of the reaction.

ex: reaction between acetic

acid and ethanol. (1 mark)

b) Hydrolysis (p:191) Neutralization (p:152)

Dissolution of a salt in water to produce

acid and alkali. (1 mark)

Reaction of acid and alkali to produce salt

and water. (1 mark)

c) Primary cells (p:209) Secondary cells (p:210)

Spontaneous irreversible reaction. Spontaneous reversible reaction.

Can not recharged. (1 mark) recharged. (1 mark)

3


Question(3) (15 marks) Firstly : 5 marks

1- Freons are consider as halogenated derivative of alkanes as CF4, diflouro methane CF2Cl2 (1 mark). it is used in air conditions and fridges also as a rushed substances to liquid and perfumes and as a cleaner of electronic sets. (1 mark) p:248. Its harms: it causes the decay of ozone layer which protect the earth against harmful effect of ultra violet rays. (½mark) p:248

2- preparation of ethelene (2½mark) (each equation has 1 mark and the condition ½mark).

(if the student collects the two steps in one correct equation and illustrates the condition of the reaction he will takes the complete marks)

Secondly(10 marks) 1- 3 marks (one mark for drawing and another for items and

one mark for total equation). Lead acid battary: (p:212) It consists of: 1 ) The anode is network of lead filled with spongy lead (pb). 2 ) The cathod is lead network filled with a paste of lead dioxide (PbO2). 3 ) Conducting electrolyte(diluted sulphuric acid). 4 ) A container made of solid rubber or from plastic materials (polystyrene) which does not affect by

acids.

The total battery reaction is: 2- a ) Le Chatelier: a French scientist put a rule describe the effect of different factors such as

concentration, temperature and pressure on the systems under equilibrium. (The changes in any of the conditions of a chemical equilibrium such as concentration, pressure or

temperature cause shift of the equilibrium in the direction which will oppose this change) (1 mark) ( p:167,177).

b ) Avogadro: deduce the relation between the equal volume of different gases which measured at the same conditions (stp) and number of molecules. (Equal volumes of gases at the same pressure and temperature contain the same number of

molecules.) (1 mark) p:145 c ) Ostwald: He described the inversely proportional relation between the extent of ionization ( α ) and

concentration (c) mole/liter for solutions. (1 mark) (P: 181) 3- (4 marks) 2 marks for each explaination.

- During hydrolysis of ammonium chloride,NH4OH is formed (weak base) and hydrochloric acid is not formed( strong electrolyte),water is ionized to produce H+ to compensate the decrease of hydroxyl ions According to Le-Chatelier principle, the concentration of H+ increase and (pH < 7). (2 marks) p:190

- Sodium carbonate solution is alkaline. (2 marks) p:189

Sodium hydroxide is not formed because it is a strong electrolyte (completely ionized) and the ions of (OH-) still in water and (H+) ions will combine with carbonate ions and carbonic acid is formed (weak electrolyte) and so the ions of (H+) will decrease from the solution and the equilibrium is disturbed. in order to attain the equilibrium according to Le-Chatelier principle, other molecules of water are ionized to compensate the decrease in (H+) ions .Consequently hydroxyl ions are accumulated and increased in concentration, to a level greater than the concentration of hydrogen ions giving (pH >7).

CH3 – CH2 – OH + HOSO3H CH3 – CH2 – OSO3H + H2O

CH3 – CH2 – OSO3H H2C = CH2 + H2SO4

O2+ H 2C = CH2H OH – 2CH – 3CH

H2SO4

180°c

180°c

80°c

NH4Cl Cl- + NH4+

H2O H+ + OH-

H2O + NH4Cl H+ + Cl- + NH4OH

2H2O 2H+ + 2OH-

Na2CO3 CO3-2 + 2Na+

Na2CO3 + 2H2O H2CO3 + 2Na+ + 2OH-

Pb + PbO2 + 4H+ + 2SO42- 2PbSO4 + 2H2O

discharge

charge

anode cathode solution

4


Question(4): (15 marks) Firstly: (8 marks):

1- (3 marks) a ) Titration it is a process it is based on measuring the amount of a reagent of known

concentration (standard solution) that is completely consumed by the analyte.(1 mark) p:152

b ) Indicators: chemical substances which change their colours in the reaction medium are used. ex: methyl orange (1 mark) p:153

c ) Ionic equilibrium: it is the equilibrium arising between molecules of a weak electrolyte and the ions resulting from it. (1 mark) p:181

2- (3 marks) a ) the additives added to alcohol are methanol, pyridine and coloured dyes (1 mark),

They are added to minimize its use in making alcoholic liquors. (½mark) P(290) b ) by blowing a balloon through a tube containing silica gel saturated with acidified

potassium dichromate. the balloon is left till the exhalation goes out. if the driver was drunk, the colour of potassium dichromate in the tube changed from orange to green colour. P(296) (1 ½ mark)

3- (2 marks) Experiment: put a small amount of an organic substance (textile-leather-paper-plastic) mixed with copper oxide (CuO) in a glass tube resists heat, heat the test tube strongly then pass the resulting gases over anhydrous white copper sulphate (CuSO4) then through lime water. (½ mark) p:237 Obs : 1) The white colour of anhydrous copper sulphate turns into blue which indicates the

absorption of (CuSO4) to water vapour which is formed from combination of oxygen from (CuO) and the hydrogen from organic compound. (½marks)

2)Lime water turns turbid due to the evolution of carbon dioxide (CO2) ,which is formed from combination of oxygen from (CuO) and the carbon from the organic compound. (½ mark)

Conclusion: The organic compound contains carbon and hydrogen. (½mark) Secondly (7marks):

1- (3 marks) : Experiment 1 mark , observation 1 mark , Conclusion 1 mark. Experiment: dilute each solution to 0.01 molar and test the electrical conductivity, then further dilute each solution to 0.001 molar and test the conductivity of each solution again ( the illumination of the lamp ). Obs: You noticed that illumination of the lamp is not affected in the case of dilution of hydrochloric acid, but the illumination increases in the case of the dilution of acetic acid. Conclusion: Covalent compounds such as hydrogen chloride and ethanoic acid ionize in water. ionization of hydrogen chloride is complete, but that of acetic acid is very limited .

2- (2 marks)

(½mark)(aq) +O 3(aq) + H-COO3O = CH2COOH + H3CH

(½mark)COOH 3) / CH+O 3) . ( H -COO3Ka = ( CH

(½mark) ×1.8 5-0.1× 10 ) = +O3(H

(½mark)molar 3-1.342 × 10 = 3- (2 marks) (1 mark for drawing and 1 mark for explanation).

The electroplating of a jug by a layer of silver. 1 ) The jug should be connected by the negative pole of

the battery (cathod). 2 ) A silver metal column is connected by

the positive pole (anode). 3 ) Electrolyte solution contains silver ions (AgNO3).

5


Question 5 (15 marks): Firstly: 5 marks.(5×1=5)

1- Because the mass of one mole of CO2 (44gm) is more than the mass of one mole of O2 (32 gm) and the two masses occupy the same volume at (stp). p: 147

2- because the small angles lead to weak overlap between the atomic orbitals. Therefore, the bonds between carbon atoms are very weak and easily broken, so these compounds are very active. p:263

3- Because the reactants volume is more than the products volume, so by increasing pressure, the direction of the reaction will be shifted forward to reduce the volume, so the rate of ammonia formation increases. p:175

4- The boiling point increases by the increase of: 1- The molecular mass ( the m.s. of sorbitol is greater than that of glycerol ). 2- The number of hydroxyl groups ( sorbitol has a greater number of OH groups )

يكتفى بنقطة واحدة ) ) 5- Because when the detergent is dissolved in water, their molecules arrange themselves

where hydrophilic tail of each molecule is directed towards the dirties and the textile adhere with them. while the hyrophilic head is directed towards water, so the detergent molecules surround the dirties completely, and with any mechanical rubbing the cleaning process stars.

Secondly(10 marks) p:275 1- 4 marks

Equivalent mass of gold = = = 65.6631 gram (1 mark)

Mass of deposited gold =

=

= 32.83 gram (1 mark)

Volume = = = 2.487 cm3 (1 mark)

The cathode equation:

(1 mark) 2- 3 marks

a ) The number of sigma bonds in the compound =7, and the number of pi bond = 3

(1 mark)

b ) Due to breaking of three pi bonds so we need 3 molecules of hydrogen, therefore

the number of hydrogen moles = 3 (1 mark)

c ) After addition of three molecules of hydrogen to the compound it will changes to

saturated (butane) C4H10 ( H3C-CH2-CH2-CH3 ) (1 mark) 3- 3 marks

Preparation of acetylene:

Drawing (2 mark)

Equation (1 mark)

اإلجابة ى نموذجانته

0 Au -+ 3e 3+ Au

CaC2 + 2H.OH Ca (OH)2 + H – C C – H

196.98 3

Quantity of electricity (coul.) × equv. mass of gold 96500

½ × 96500 × 65.6631 96500

mass

density

32.83

13.2

atomic mass valence

ــ14 arab republic of egypt لوأ / ج.ع.ث ح 14 2...

Documents