Class 12 Alcohols, Phenols and Ethers Mock Test (CBSE)

Topics in Alcohols, Phenols and Ethers

• Classification and nomenclature
• Structures of functional groups
• Preparation of alcohols
• Preparation of phenols
• Physical properties of alcohols and phenols
• Chemical reactions of alcohols and phenols
• Acidity of alcohols and phenols
• Some commercially important alcohols
• Preparation of ethers
• Physical and chemical properties of ethers

Alcohols, Phenols and Ethers practice questions with answers

1. Q1Assertion and reason·1 mark
   Assertion (A): Preparation of tert-butyl ethyl ether is successfully carried out by reacting sodium ethoxide with tert-butyl chloride. Reason (R): Reaction of tertiary alkyl halides with sodium alkoxides mainly results in elimination rather than substitution to yield alkenes.

   1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   2. (b)Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
   3. (c)Assertion (A) is true but Reason (R) is false.
   4. (d)Assertion (A) is false but Reason (R) is true.
   Show answer and step marks

   1. Correct option: (d) Assertion (A) is false but Reason (R) is true.+1

   Answer: (d)
2. Q2Multiple choice·1 mark
   Which of the following is obtained as a byproduct along with phenol when cumene is oxidized in the presence of air followed by treatment with dilute acid?

   1. (a)$CH_3COOH$
   2. (b)$CH_3CHO$
   3. (c)$CH_3COCH_3$
   4. (d)$HCHO$
   Show answer and step marks

   1. Correct option: (c) $CH_3COCH_3$. Cumene is oxidized in the presence of air to cumene hydroperoxide, which on acid hydrolysis yields phenol and acetone ($CH_3COCH_3$).+1

   Answer: (c)
3. Q3Multiple choice·1 mark
   Among the following compounds, which one possesses the highest boiling point?

   1. (a)$CH_3CH_2CH_2CH_3$
   2. (b)$CH_3CH_2CH_2CH_2OH$
   3. (c)$CH_3CHO$
   4. (d)$CH_3CH_2OCH_2CH_3$
   Show answer and step marks

   1. Correct option: (b) $CH_3CH_2CH_2CH_2OH$. Alcohols have significantly higher boiling points than ethers, alkanes, and aldehydes of comparable molecular masses due to the presence of strong intermolecular hydrogen bonding.+1

   Answer: (b)
4. Q4Assertion and reason·1 mark
   Assertion (A): Treatment of phenol with chloroform and aqueous sodium hydroxide introduces an aldehyde group at an ortho-position of the benzene ring. Reason (R): The electrophile attacking the phenoxide ion in this reaction is dichlorocarbene ($:CCl_2$).

   1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   2. (b)Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
   3. (c)Assertion (A) is true but Reason (R) is false.
   4. (d)Assertion (A) is false but Reason (R) is true.
   Show answer and step marks

   1. Correct option: (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).+1

   Answer: (a)
5. Q5Short answer·2 marks
   Write the balanced chemical equation for the reaction of phenol with aqueous bromine. State the visual observation associated with this reaction.
   Show answer and step marks

   1. Balanced chemical equation: $\text{C}_6\text{H}_5\text{OH} + 3\text{Br}_2\text{(aq)} \rightarrow \text{C}_6\text{H}_2\text{Br}_3\text{OH} + 3\text{HBr}$+1
   2. Observation: a white precipitate (of $2,4,6$-tribromophenol) forms, as the brown colour of bromine water disappears.+1

   Answer: $\text{C}_6\text{H}_5\text{OH} + 3\text{Br}_2 \rightarrow \text{C}_6\text{H}_2\text{Br}_3\text{OH}$ ($2,4,6$-tribromophenol) $+ 3\text{HBr}$; a white precipitate forms.
6. Q6Short answer·2 marks
   Write the chemical equation for the reaction of phenol with concentrated nitric acid in the presence of concentrated sulphuric acid. Give the IUPAC name of the major product formed.
   Show answer and step marks

   1. Balanced chemical equation: $\text{C}_6\text{H}_5\text{OH} + 3\text{HNO}_3 \xrightarrow{\text{conc. H}_2\text{SO}_4} \text{C}_6\text{H}_2(\text{NO}_2)_3\text{OH} + 3\text{H}_2\text{O}$+1
   2. IUPAC name of the major product: $2,4,6$-trinitrophenol (common name picric acid).+1

   Answer: $\text{C}_6\text{H}_5\text{OH} + 3\text{HNO}_3 \xrightarrow{\text{conc. H}_2\text{SO}_4} \text{C}_6\text{H}_2(\text{NO}_2)_3\text{OH} + 3\text{H}_2\text{O}$; $2,4,6$-trinitrophenol (picric acid).

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