Chapter 11 Alcohols, Phenols And Ethers

Question 1. Monochlorination of toluene in sunlight followed by hydrolysis with aq. NaOH yields.

(i) o-Cresol

(ii) m-Cresol

(iii) 2, 4-Dihydroxytoluene

(iv) Benzyl alcohol

Question 2. How many alcohols with molecular formula $C_4H_{10}O$ are chiral in nature?

(i) 1

(ii) 2

(iii) 3

(iv) 4

Question 3. What is the correct order of reactivity of alcohols in the following reaction?

$R—OH + HCl \xrightarrow{ZnCl_2} R—Cl + H_2O$

(i) 1° > 2° > 3°

(ii) 1° < 2° > 3°

(iii) 3° > 2° > 1°

(iv) 3° > 1° > 2°

Question 4. $CH_3CH_2OH$ can be converted into $CH_3CHO$ by ______________.

(i) catalytic hydrogenation

(ii) treatment with $LiAlH_4$

(iii) treatment with pyridinium chlorochromate

(iv) treatment with $KMnO_4$

Question 5. The process of converting alkyl halides into alcohols involves_____________.

(i) addition reaction

(ii) substitution reaction

(iii) dehydrohalogenation reaction

(iv) rearrangement reaction

Question 6. Which of the following compounds is aromatic alcohol?

(i) A, B, C, D

(ii) A, D

(iii) B, C

(iv) A

Question 7. Give IUPAC name of the compound given below.

(i) 2-Chloro-5-hydroxyhexane

(ii) 2-Hydroxy-5-chlorohexane

(iii) 5-Chlorohexan-2-ol

(iv) 2-Chlorohexan-5-ol

Question 8. IUPAC name of m-cresol is __________.

(i) 3-methylphenol

(ii) 3-chlorophenol

(iii) 3-methoxyphenol

(iv) benzene-1,3-diol

Question 9. IUPAC name of the compound is ______________.

(i) 1-methoxy-1-methylethane

(ii) 2-methoxy-2-methylethane

(iii) 2-methoxypropane

(iv) isopropylmethyl ether

Question 10. Which of the following species can act as the strongest base?

(i) $^\ominus OH$

(ii) $^\ominus OR$

(iii) $^\ominus OC_6H_5$

(iv)

Question 11. Which of the following compounds will react with sodium hydroxide solution in water?

(i) $C_6H_5OH$

(ii) $C_6H_5CH_2OH$

(iii) $(CH_3)_3COH$

(iv) $C_2H_5OH$

Question 12. Phenol is less acidic than ______________.

(i) ethanol

(ii) o-nitrophenol

(iii) o-methylphenol

(iv) o-methoxyphenol

Question 13. Which of the following is most acidic?

(i) Benzyl alcohol

(ii) Cyclohexanol

(iii) Phenol

(iv) m-Chlorophenol

Question 14. Mark the correct order of decreasing acid strength of the following compounds.

(i) e > d > b > a > c

(ii) b > d > a > c > e

(iii) d > e > c > b > a

(iv) e > d > c > b > a

Question 15. Mark the correct increasing order of reactivity of the following compounds with HBr/HCl.

(i) a < b < c

(ii) b < a < c

(iii) b < c < a

(iv) c < b < a

Question 16. Arrange the following compounds in increasing order of boiling point.

Propan-1-ol, butan-1-ol, butan-2-ol, pentan-1-ol

(i) Propan-1-ol, butan-2-ol, butan-1-ol, pentan-1-ol

(ii) Propan-1-ol, butan-1-ol, butan-2-ol, pentan-1-ol

(iii) Pentan-1-ol, butan-2-ol, butan-1-ol, propan-1-ol

(iv) Pentan-1-ol, butan-1-ol, butan-2-ol, propan-1-ol

Question 17. Which of the following are used to convert RCHO into $RCH_2OH$?

(i) $H_2/Pd$

(ii) $LiAlH_4$

(iii) $NaBH_4$

(iv) Reaction with RMgX followed by hydrolysis

Question 18. Which of the following reactions will yield phenol?

(i)

(ii)

(iii)

(iv)

Question 19. Which of the following reagents can be used to oxidise primary alcohols to aldehydes?

(i) $CrO_3$ in anhydrous medium.

(ii) $KMnO_4$ in acidic medium.

(iii) Pyridinium chlorochromate.

(iv) Heat in the presence of Cu at 573K.

Question 20. Phenol can be distinguished from ethanol by the reactions with _________.

(i) $Br_2$/water

(ii) Na

(iii) Neutral $FeCl_3$

(iv) All the above

Question 21. Which of the following are benzylic alcohols?

(i) $C_6H_5—CH_2—CH_2OH$

(ii) $C_6H_5—CH_2OH$

(iii)

(iv)

Question 22. What is the structure and IUPAC name of glycerol?

Question 23. Write the IUPAC name of the following compounds.

(A)

(B)

Question 24. Write the IUPAC name of the compound given below.

Question 25. Name the factors responsible for the solubility of alcohols in water.

Question 26. What is denatured alcohol?

Question 27. Suggest a reagent for the following conversion.

Question 28. Out of 2-chloroethanol and ethanol which is more acidic and why?

Question 29. Suggest a reagent for conversion of ethanol to ethanal.

Question 30. Suggest a reagent for conversion of ethanol to ethanoic acid.

Question 31. Out of o-nitrophenol and p-nitrophenol, which is more volatile? Explain.

Question 32. Out of o-nitrophenol and o-cresol which is more acidic?

Question 33. When phenol is treated with bromine water, white precipitate is obtained. Give the structure and the name of the compound formed.

Question 34. Arrange the following compounds in increasing order of acidity and give a suitable explanation.

Phenol, o-nitrophenol, o-cresol

Question 35. Alcohols react with active metals e.g. Na, K etc. to give corresponding alkoxides. Write down the decreasing order of reactivity of sodium metal towards primary, secondary and tertiary alcohols.

Question 36. What happens when benzene diazonium chloride is heated with water?

Question 37. Arrange the following compounds in decreasing order of acidity.

$H_2O, ROH, HC \equiv CH$

Question 38. Name the enzymes and write the reactions involved in the preparation of ethanol from sucrose by fermentation.

Question 39. How can propan-2-one be converted into tert- butyl alcohol?

Question 40. Write the structures of the isomers of alcohols with molecular formula $C_4H_{10}O$. Which of these exhibits optical activity?

Question 41. Explain why is OH group in phenols more strongly held as compared to OH group in alcohols.

Question 42. Explain why nucleophilic substitution reactions are not very common in phenols.

Question 43. Preparation of alcohols from alkenes involves the electrophilic attack on alkene carbon atom. Explain its mechanism.

Question 44. Explain why is $O=C=O$ nonpolar while R—O—R is polar.

Question 45. Why is the reactivity of all the three classes of alcohols with conc. HCl and $ZnCl_2$ (Lucas reagent) different?

Question 46. Write steps to carry out the conversion of phenol to aspirin.

Question 47. Nitration is an example of aromatic electrophilic substitution and its rate depends upon the group already present in the benzene ring. Out of benzene and phenol, which one is more easily nitrated and why?

Question 48. In Kolbe’s reaction, instead of phenol, phenoxide ion is treated with carbon dioxide. Why?

Question 49. Dipole moment of phenol is smaller than that of methanol. Why?

Question 50. Ethers can be prepared by Williamson synthesis in which an alkyl halide is reacted with sodium alkoxide. Di-tert-butyl ether can’t be prepared by this method. Explain.

Question 51. Why is the $C—O—H$ bond angle in alcohols slightly less than the tetrahedral angle whereas the $C—O—C$ bond angle in ether is slightly greater?

Question 52. Explain why low molecular mass alcohols are soluble in water.

Question 53. Explain why p-nitrophenol is more acidic than phenol.

Question 54. Explain why alcohols and ethers of comparable molecular mass have different boiling points?

Question 55. The carbon-oxygen bond in phenol is slightly stronger than that in methanol. Why?

Question 56. Arrange water, ethanol and phenol in increasing order of acidity and give reason for your answer.

Question 57. Match the structures of the compounds given in Column I with the name of the compounds given in Column II.

Column I	Column II
(i)	(a) Hydroquinone
(ii)	(b) Phenetole
(iii)	(c) Catechol
(iv)	(d) o-Cresol
(v)	(e) Quinone
(vi)	(f) Resorcinol
	(g) Anisole

Question 58. Match the starting materials given in Column I with the products formed by these (Column II) in the reaction with HI.

Column I	Column II
(i) $CH_3—O—CH_3$	(a)
(ii)	(b)
(iii)	(c)
(iv)	(d) $CH_3—OH + CH_3—I$
	(e)
	(f)
	(g)

Question 59. Match the items of column I with items of column II.

Question 60. Match the items of column I with items of column II.

Question 61. Assertion : Addition reaction of water to but-1-ene in acidic medium yields butan-1-ol

Reason : Addition of water in acidic medium proceeds through the formation of primary carbocation.

Question 62. Assertion : p-nitrophenol is more acidic than phenol.

Reason : Nitro group helps in the stabilisation of the phenoxide ion by dispersal of negative charge due to resonance.

Question 63. Assertion : IUPAC name of the compound is 2-Ethoxy-2-methylethane.

Reason : In IUPAC nomenclature, ether is regarded as hydrocarbon derivative in which a hydrogen atom is replaced by —OR or —OAr group [where R = alkyl group and Ar = aryl group]

Question 64. Assertion : Bond angle in ethers is slightly less than the tetrahedral angle.

Reason : There is a repulsion between the two bulky (—R) groups.

Question 65. Assertion : Boiling points of alcohols and ethers are high.

Reason : They can form intermolecular hydrogen-bonding.

Question 66. Assertion : Like bromination of benzene, bromination of phenol is also carried out in the presence of Lewis acid.

Reason : Lewis acid polarises the bromine molecule.

Question 67. Assertion : o-Nitrophenol is less soluble in water than the m- and p-isomers.

Reason : m- and p- Nitrophenols exist as associated molecules.

Question 68. Assertion : Ethanol is a weaker acid than phenol.

Reason : Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH.

Question 69. Assertion : Phenol forms 2, 4, 6 – tribromophenol on treatment with $Br_2$ in carbon disulphide at 273K.

Reason : Bromine polarises in carbon disulphide.

Question 70. Assertion : Phenols give o- and p-nitrophenol on nitration with conc. $HNO_3$ and $H_2SO_4$ mixture.

Reason : —OH group in phenol is o–, p– directing.

Question 71. Write the mechanism of the reaction of HI with methoxybenzene.

Question 72. (a) Name the starting material used in the industrial preparation of phenol.

(b) Write complete reaction for the bromination of phenol in aqueous and non aqueous medium.

(c) Explain why Lewis acid is not required in bromination of phenol?

Question 73. How can phenol be converted to aspirin?

Question 74. Explain a process in which a biocatalyst is used in industrial preparation of a compound known to you.