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Quarterly Test-1

Date : _________ Chemistry

BATCH Duration: 3 Hr. Max. Marks : 70 XII

1. Identify the compound Y in the following reaction.

(a) (b)

(c) (d)

2. Among the alkenes which one produces tertiary butyl alcohol on acid hydration

(a) (CH3)2C = CH2 (b) CH3 – CH = CH – CH3

(c) CH3 – CH2 – CH = CH2 (d) CH3 – CH = CH2

OR An electrochemical cell can behave like an electrolytic cell when _______ (a) Ecell = 0 (b) Ecell > Eext (c) Eext > Ecell (d) Ecell = Eext

3. Maximum amount of a solid solute that can be dissolved in a specified amount of a given liquid solvent does not depend upon _____________

(a) Temperature (b) Nature of solute (c) Pressure (d) Nature of solvent

OR Which of the following does not give Fehling solution test? (a) Formaldehyde (b) Acetaldehyde (c) Benzaldehyde (d) Propionaldehyde 4. Toluene reacts with a halogen in the presence of iron (III) chloride giving ortho and para halo

compounds. The reaction is (a) electrophilic elimination reaction (b) electrophilic substitution reaction (c) free radical addition reaction (d) nucleophilic substitution reaction

General instruction: All questions are compulsory. Q. 1 to Q. 20 are 1 mark questions. Q. 21 to Q. 27 are 2 marks questions. Q. 28 to Q. 34 are 3 marks questions. Q. 35 to Q. 37 are five marks questions.

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5. Among the following, which is least acidic?

(a) Phenol (b) o-cresol (c) p-nitrophenol (d) p-chlorophenol

OR The quantity of charge required to obtain one mole of aluminium from Al2O3 is ___________. (a) 1F (b) 6F (c) 3F (d) 2F 6. Low concentration of oxygen in the blood and tissues of people living at high altitude is due to

___________ (a) low temperature (b) low atmospheric pressure (c) high atmospheric pressure (d) both low temperature and high atmospheric pressure

OR Which of the following will have the highest boiling point? (a) Methanal (b) Ethanal (c) Propanal (d) Hexanone 7. In which of the following molecules carbon atom marked with asterisk (*) is asymmetric?

(a) (i), (ii), (iii) and (iv) (b) (i), (ii) and (iii) (c) (ii), (iii) and (iv) (d) (i), (iii) and (iv) 8. Anisole can be prepared by the action of methyl iodide on sodium phenoxide. The reaction is

called: (a) Fittig’s reaction (b) Williamson’s reaction (c) Wurtz’s reaction (d) Etard’s reaction

OR ^°m (NH4OH) is equal to _______________ (a) ^°m (NH4OH) + ^°m (NH4Cl) – ^° (HCl) (b) ^°m (NH4Cl) + ^°m (NaOH) – ^° (NaCl) (c) ^°m (NH4Cl) + ^°m (NaCl) – ^° (NaOH) (d) ^°m (NaOH) + ^°m (NaCl) – ^° (NH4Cl) 9. Which of the following aqueous solutions should have the highest boiling point?

(a) 1.0 M NaOH (b) 1.0 M Na2SO4 (c) 1.0 M NH4NO3 (d) 1.0 M KNO3

OR Cannizzaro’s reaction is not given by _____________.

(a) (b)

(c) HCHO (d) CH3CHO 10. An organic compound A(C4H9Cl) on reaction with Na/diethyl ether gives a hydrocarbon which

on monochlorination gives only monochloro derivative then, A is: (a) iso-butyl chloride (b) secondary butyl chloride (c) n-butyl chloride (d) t-butyl chloride

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11. The dipole moment of chlorobenzene is lower than that of cyclohexylchloride. Why?

12. Which colligative property is preferred for the molar mass determination of macro molecules? OR

What is name of the compound A?

13. Give the IUPAC name of

OR Under what condition Ecell = 0 14. What are ambient nucleophiles? Explain with an example.

15. How will you distinguish between ethanol and propanol?

OR What is the electrolyte used in dry cell? 16. Henry law constant for two gases are 21.5 and 49.5 atm, which gas is more soluble.

OR Which is the most suitable reagent for the following conversion?

17. Give the IUPAC name of DDT. 18. Give Kolbe’s reaction.

OR Why does conductivity of a solution decrease with dilution? 19. Two liquids A and B boils at 120°C and 160°C respectively. Which one of them will be having

higher vapour pressure at 70°C? OR

In Clemmensen Reduction carbonyl compound is treated with ___________. 20. Out of SN1 and SN2, which reaction occurs with

(a) inversion of configuration (b) Racemisation? 21. The vapour pressure of water is 12.3 kPa at 300 K. Calculate vapour pressure of 1 molal

solution of a non-volatile solute in it. OR

Which type of aldehydes give cannizzaro reaction? Give Example. 22. Which compound undergoes SN1 reaction faster and why?

(a) CH3—CH2—CH2—Br or CH2= CH—CH2Br (b) CH3—Br or CH3—I 23. Write the mechanism of hydration of ethene to yield ethanol.

OR (a) Can you store copper sulphate in zinc pot? Why? Given E°Zn2+/Zn = –0.76 V; E°Cu2+/Cu = 0.34 V. (b) Write the reactions at cathode during the electrolysis of NaCl (in aqueous solution).

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24. Draw a well labelled graph to show the elevation in boiling point of a solvent in presence of a solute.

OR Would you expect benzaldehyde to be more reactive or less reactive in nucleophilic addition

reactions than propanal? Explain your answer. 25. The treatment of alkylchlorides with aqueous KOH leads to the formation of alcohols but in

presence of alcoholic KOH, alkenes are major products. Explain. 26. How would you synthesise the following: (a) Benzoquinone from phenol (b) Picric acid from phenol

OR A solution of Ni(NO3)2 is electrolysed between platinum electrodes using a current of 5.0 ampere

for 20 minutes. What mass of nickel will be deposited at the cathode? (At. mass of Ni = 58.7 u) 27. Given reason for the following: (a) Aquatic species are more comfortable in cold water than in warm water. (b) RBC swell up and finally burst when placed in 0.1% NaCl solution.

OR Write a test to differentiate between pentan-2-one and pentan-3-one. Give equations. 28. 2g of C6H5COOH dissolved in 25g of benzene shows depression in freezing point equal to 1.62K.

Molar freezing point depression constant for benzene is 4.9 K kg mol–1. What is the percentage association of acid if it forms a dimer in solution?

OR A bottle of commercial H2SO4 [density = 1.787 g/mL] is labelled as 86% by mass. (i) What is the

molarity of the acid? (ii) What volume of the acid has to be used to make 1 litre 0.2 M H2SO4? (iii) What is the molality of the acid?

OR (a) What product will be formed on heating propanal with 2-methylpropanal in the presence of

NaOH? What products will be formed? Write the name of the reaction also. (b) Arrange the following in decreasing order of their acidic strength. CH3CH2OH, CH3COOH, ClCH2COOH, FCH2COOH, C6H5CH2COOH 29. What happens when: (a) cumene is oxidised in the presence of air and the product formed is treated with dilute

acid. (b) phenol is treated with chloroform in presence of dilute NaOH. (c) bromine in carbon disulphide reacts with phenol.

OR Conductivity of 0.00241 M acetic acid is 7.896 × 10–5 S cm–1. Calculate its molar conductivity

and if Λ°m for acetic acid is 390.5 S cm2 mol–1, what is its dissociation constant? 30. An organic compound ‘A’ with molecular formula C3H6 on treatment with aqueous H2SO4 give ‘B’

which on treatment with HCl and ZnCl2 gives compound ‘C’. The compound ‘C’ on treatment with ethanolic KOH gives back the compound A. Identify the compounds A, B and C.

31. Arrange the following in the increasing order of property shown: (a) Methanol, Ethanol, Diethylether, Ethylene-glycol. (Boiling points) (b) Phenol, 2,4-dinitrophenol, m-nitrophenol, p-nitrophenol. (Acidic strength) (c) Chloropropane, isopropyl chloride, chlorobutane, chloroform (Boiling point)

OR Give the electrochemical theory of rusting of iron. 32. In a solution of urea, 3.0 g of it is dissolved in 100 mL of water. What will be the freezing point

of this solution? [Kf for water = 1.86 K kg mol-1, molar mass of urea = 60 g mol-1]. OR

An organic compound (A) with molecular formula C8H8O forms an orange-red precipitate with 2,4-DNP reagent and gives yellow precipitate on heating with iodine in the presence of sodium hydroxide. It neither reduces Tollens’ or Fehlings’ reagent, nor does it decolourise bromine water or Baeyer’s reagent. On drastic oxidation with chromic acid, it gives a carboxylic acid (B) having

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molecular formula C7H6O2. Identify the compounds (A) and (B) and explain the reactions involved.

33. Give a chemical test to distinguish between following pairs of compounds: (a) Chlorobenzene and cyclohexylchloride (b) Vinyl chloride and ethyl chloride (c) N-propyl bromide and isopropyl bromide 34. Bring out the following conversions: (a) Ethyl magnesium chloride to Propan-l-ol (b) Aniline to phenol (c) Benzyl alcohol to 2-phenylethanoic acid

OR Predict the products of electrolysis in each of the following: (a) An aqueous solution of AgNO3 with platinum electrodes. (b) An aqueous solution of H2SO4 with platinum electrodes. 35. (a) Complete the following reactions:

(i) (ii)

(iii)

(b) The following is not an appropriate reaction for the preparation of t-butyl ethyl ether.

(i) What would be the major product of this reaction? (ii) Write a suitable reaction for preparation of t-butyl ether.

OR (a) Write the Nernst equation and calculate emf of the cells at 298 K. Mg(s) | Mg2+ (0.001 M) || Cu2+ (0.0001 M) | Cu (s) E°Cu2+/Cu = 0.34 E°Mg2+/Mg = –2.37 (b) What advantage do the fuel cells have over primary and secondary batteries? 36. (a) State Henry’s law and give its one application. (b) An aqueous solution of 1.248 g of BaCl2 in 100 g of water is found to boil at 100.08°C.

Calculate the degree of dissociation of BaCl2. [Kb(H2O) = 0.52 k/m]. Molar mass of barium = 137 g/mol.

OR (a) Write chemical reactions to affect the following transformations: (i) Butan-1-ol to butanoic acid (ii) Benzyl alcohol to phenylethanoic acid (iii) 3-Nitrobromobenzene to 3-nitrobenzoic acid (b) An organic compound with the molecular formula C9H10O forms 2,4-DNP derivative,

reduces Tollens’ reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1,2-benzenedicarboxylic acid. Identify the compound.

37. (a) Primary alkyl halide C4H9Br (a) reacted with alcoholic KOH to give compound (b), compound (b) is reacted with HBr to give (c) which is an isomer of (a). When (a) is reacted with sodium metal it gives compound (d), C8H18 which is different from the compound formed when n-butyl bromide is reacted with sodium. Give the structural formula of (a) and write equations for all the reactions.

(b) Convert tert-butyl bromide to isobutyl bromide.

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Hints/Solutions to Quarterly Test-1

Date : _________ Chemistry

BATCH Duration: 3 Hr. Max. Marks : 70 XII

1. (a) 2. (a) OR (c) 3. (c) OR (c) 4. (b)

5. (b) OR (c) 6. (a) OR (d)

7. (b) 8. (b) OR (b)

9. (b) OR (d) 10. (d) 11. Due to partial double bond between chlorine and ring, bond length decreases.

12. Osmotic Pressure.

OR

Prop-1-ene-2-ol 13. 2,6-dimethylphenol

OR At equilibrium

14.

15. By iodoform test: CH3CH2OH give yellow precipitate but CH3CH2CH2OH does not.

OR A paste of NH4Cl, MnO2 and C. 16. Gas with lower KH value.

OR I2 + NaOH or NaOI 17. IUPAC Name is 2, 2-bis-(4-chlorophenyl)-l, 1, 1-trichloroethane.

18.

OR

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Conductivity decreases with decrease in concentration as the number of ions per unit volume that carry the current in a solution decrease on dilution.

19. Liquid A.

OR Zinc amalgam + HCl 20. (a) SN2 involves inversion of configuration (b) SN1 involves Racemisation

21.

OR

Aldehydes having no alpha hydrogen. Eg. HCHO. 22. (a) CH2=CH–CH2Br, as intermediate formed will be stable by resonance.

(b) CH3-I, due to larger size of I.

23.

OR (a) No, because zinc is more reactive than copper. E°cell = E°Cu2+/Cu – E°Zn2+/Zn = 1.10 V Since E°cell is positive, the reaction can take place.

(b) 2H2O + 2e– → H2 + 2OH– 24. Refer Text

OR The carbon atom of the carbonyl group of benzaldehyde is less electrophilic than carbon atom of

the carbonyl group present in propanal. The polarity of the carbonyl group is reduced in benzaldehyde due to resonance as shown below and hence it is less reactive than propanal.

25. Aqueous KOH is alkaline in nature i.e. it dissociates to produce a hydroxide ion. These hydroxide ions act as a strong nucleophile and replace the halogen atom in an alkyl halide. This results in the formation of alcohol molecules and the reaction is known as nucleophilic substitution reaction.

Alcoholic, KOH, especially in ethanol, produces C2H5O− ions. The C2H5O− ion is a stronger base than the OH−ion. Thus, the former abstracts the β-hydrogen of an alkyl halide to produce alkenes. This reaction is known as elimination reaction.

26. (a) Acidic K2Cr2O7 (b) Conc. HNO3 and conc. H2SO4 OR

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27. (a) Solubility of a gas increases with decrease of temperature. Hence aquatic species are more comfortable in cold waters rather than in warm waters.

(b) 0.1% salt solution being hypotonic the water will enter to RBC causing swelling and bursting of RBC. As the concentration of the water is less than the NaCl solution so water will enter into RBC.

OR Iodoform test. CH3CH2CH2COCH3 + NaOI CH3CH2CH2COONa + CHI3 (Yellow ppt) CH3CH2COCH2CH3 + NaOI No Reaction. 28. W2 = 2g; Kf = 4.9K kg mol–1; W2 = 25g; ∆Tf = 1.62K Substituting, this in the equation ∆Tf = (Kf × W2 × 1000) /(M2 × W1) Therefore, M2 = (4.9 × 2 × 1000)/(25 × 1.62 = 241.98 g mol–1 Thus experimental molar mass of benzoic acid in benzene is = 241.98 g mol–1 2C6H5COOH → (C6H5COOH)2 If x represents the degree of association of the solute then we would have (1 – x) mol of benzoic

acid left in unassociated form and correspondingly x/2 as associated moles of benzoic acid at equilibrium is : 1 – x + x/2 = 1 – x/2

Thus, total number of moles of particles at equilibrium equals van’t Hoff factor i, But i = Normal molar mass / Abnormal molar mass = 122 g mol–1 / 241.98 g mol–1 Or x/2 = 1 – 122/ 241.98 = 1 – 0.504 = 0.496 Or x = 2 × 0.496 = 0.992 Therefore, degree of association of benzoic acid in benzene is 99.2%.

OR Molarity = Moles of solute/Volume of solution in L = Mass of solute/M. wt. of solute/Mass of solution/density of solution × 1000 M = 86/98/100/1.787 × 1000 = 0.8775/55.5 × 1000 = 15.81 M M1V1 = M1V2 M1 = 15.81, V1 = ? M2 = 0.2, V2 = 1 L = 1000 ml 15.81 × V1 = 0.2 × 1000 or V1 = 0.2 × 1000/15.81 = 12.65 ml Amount of acid to be used to make 1 L of 0.2 M H2SO4 = 12.65

OR (a) It is cross aldol condensation.

(b) FCH2COOH > ClCH2COOH > C6H5CH2COOH > CH3COOH > CH3CH2OH 29. (a) Phenol is formed. (b) Salicyaldehyde is formed.

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(c) Mixture of 2-bromophenol and 4-bromophenol is obtained. OR

Λ°m = 32.765 cm2 mol–1 and Ka = 1.86 × 10–5 mol–1 30. A= Propene B= Propan-2-ol C= 2-chloropropane 31. (a) Diethylether < methanol < ethanol < ethylene glycol (b) Phenol < m-nitrophenol < p-nitrophenol < 2,4-dinitrophenol (c) Chloroform < isopropylchloride < chloropropane < chlorobutane

OR Refer Text. 32. Use formula, ∆Tf = Kf × m

OR

33. (a) Cyclohexylchloride will react with AgNO3 to give white ppt. (b) Vinyl chloride will decolourise bromine water. (c) Isopropyl chloride will react with aq. KOH to give isopropyl alcohol which will give yellow

ppt. of iodoform with NaOI. 34. Refer text.

OR Refer NCERT. 35. (a) (i) CH3CH2OHCH3 (ii) Aspirin (iii) C6H5OH and C2H5Br

(b)

OR

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36. (a) Refer Text

(b)

OR

(a)

(b) 37. (a) Ans 21 from NCERT solutions.

(b)