Free NCERT Solutions For Class 12 Chemistry Chapter 11 : Alcohols, Phenols, and Ethers Free PDF Download

NCERT Exercise

Question 1:
Write IUPAC names of the following compounds.

Question 2:
Write structures of the compounds whose IUPAC names are as follows:
(i) 2-Methylbutan-2-ol
(ii) 1-Phenylpropan-2-ol
(iii) 3,5-Dimethylhexane -1, 3, 5-triol
(iv) 2,3 -Diethylphenol
(v) 1 -Ethoxypropane
(vi) 2-Ethoxy-3-methylpentane
(vii) Cyclohexylmethanol
(viii) 3-Cyclohexylpentan-3-ol
(ix) Cyclopent-3-en-1-ol
(x) 3-Chloromethylpentan- 1-ol

Question 3:
(i) Draw the structures of all isomeric alcohols of molecular formula C H O 5 12 and give their IUPAC names.
(ii) Classify the isomers of alcohols in question 11.3 (i) as primary, secondary and tertiary alcohols.

Question 4:
Explain why propanol has higher boiling point than that of the hydrocarbon, butane?

Question 5:
Alcohols are comparatively more soluble in water than hydrocarbons of comparable molecular masses. Explain this fact.

Question 7:
Give the structures and IUPAC names of monohydric phenols of molecular formula, C H O 7 8
.

Question 8:
While separating a mixture of ortho and para nitrophenols by steam distillation, name the isomer which will be steam volatile. Give reason

Question 9:
Give the equations of reactions for the preparation of phenol from cumene.

Question 10:
Write chemical reaction for the preparation of phenol from chlorobenzene.

Question 12:
You are given benzene, conc. H SO2 4 and NaOH . Write the equations for the preparation of phenol using these reagents.

Question 13:
Show how will you synthesize:
(I) 1-phenylethanol from a suitable alkene.
(ii) cyclohexylmethanol using an alkyl halide by an SN2 reaction.
(iii) pentan-1-ol using a suitable alkyl halide?

Question 14:
Give two reactions that show the acidic nature of phenol. Compare acidity of phenol with that of ethanol.

Question 15:
Explain why is ortho nitrophenol more acidic than ortho methoxyphenol?

Question 16:
Explain how does the -OH group attached to a carbon of benzene ring activate it towards electrophilic substitution?

Question 17:
Give equations of the following reactions:
(i) Oxidation of propan-1-ol with alkaline KMnO4 solution.
(ii) Bromine in CS2 with phenol.
(iii) Dilute HNO3 with phenol.
(iv) Treating phenol with chloroform in presence of aqueous NaOH .

Question 18:
Explain the following with an example.
(i) Kolbe’s reaction.
(ii) Reimer-Tiemann reaction.
(iii) Williamson ether synthesis.
(iv) Unsymmetrical ether

Question 19:
Write the mechanism of acid-catalyzed dehydration of ethanol to yield ethene.

Question 20:
How are the following conversions carried Out?
(i) Propene->Propan-2-ol
(ii) Benzyl chloride.->Benzyl alcohol
(iii) Ethyl magnesium chloride ->Propan-l-ol.
(iv) Methyl magnesium bromide ->2-Methylpropan-2-ol.

Solution 20:

Question 21:
Name the reagents used in the following reactions:
(i) Oxidation of a primary alcohol to carboxylic acid.
(ii) Oxidation of a primary alcohol to aldehyde.
(iii) Bromination of phenol to 2,4,6-tribromophenol.
(iv) Benzyl alcohol to benzoic acid.
(v) Dehydration of propan-2-ol to propene.
(vi) Butan-2-one to butan-2-ol.

Question 23:
Give IUPAC names of the following ethers:

Question 24:
Write the names of reagents and equations for the preparation of the following ethers by Williamson’s synthesis:
(I) 1-Propoxypropane
(ii) Ethoxybenzene
(iii) 2-Methoxy-2-methylpropane
(iv) 1-Methoxyethane

Question 25:
Illustrate with examples the limitations of Williamson synthesis for the preparation of certain types of ethers.

Question 26:
How is 1-propoxypropane synthesised from propan-1-ol? Write mechanism of this reaction

Question 27:
Preparation of ethers by acid dehydration of secondary or tertiary alcohols is not a suitable
method. Give reason.

Question 28:
Write the equation of the reaction of hydrogen iodide with:
(i) 1-propoxypropane
(ii) Methoxybenzene and
(iii) Benzylethylether

Question 29:
Explain the fact that in aryl alkyl ethers.
(i) The alkoxy group activates the benzene ring towards electrophilic substitution and
(ii) It directs the incoming substituents to ortho and para positions in benzene ring.

Question 30:
Write the mechanism of the reaction of HI with methoxymethane.

Question 31:
Write equations of the following reactions:
(i) Friedel-Crafts reaction —alkylation of anisole.
(ii) Nitration of anisole.
(iii) Bromination of anisole in ethanoic acid medium.
(iv) Friedel-Craft’s acetylation of anisole.

Solution 31:

Question 32:
Show how would you synthesize the following alcohols from appropriate alkenes?

Question 33:
When 3-methylbutan-2-ol is treated with HBr, the following reaction takes place:

Text solution

Question 1:
Classify the following as primary, secondary and tertiary alcohols:

Question 4:
Show how are the following alcohols prepared by the reaction of a suitable Grignard reagent on methanal?

Question 5:
Write structures of the products of the following reactions:

Question 7:
Predict the major product of acid catalyzed dehydration of
(i) 1-methylcyclohexanol and
(ii) butan-1-ol

Question 8:
Ortho and para nitrophenols are more acidic than phenol. Draw the resonance structures of the corresponding phenoxide ions.

Question 9:
Write the equations involved in the following reactions:
(I) Reimer-Tiemann reaction
(ii) Kolbe’s reaction

Question 10:
Write the reactions of Williamson synthesis of 2-ethoxy-3-methylpentane starting from ethanol and 3-methylpentan-2-ol

Question 11:
Which of the following is an appropriate set of reactants for the preparation of 1- methoxy-4- nitrobenzene and why?

Question 12:
Predict the products of the following reactions: