CBSE Class 12 Chemistry Aldehydes Ketones and Carboxylic Acids MCQs Set 08

Stand Alone MCQs

Question. Which of the following compounds will give butanone on oxidation with alkaline \( KMnO_4 \) solution?
(a) Butan-1-ol
(b) Butan-2-ol
(c) Both of these
(d) None of the options
Answer: (b) Butan-2-ol

Question. What kind of compounds undergo Cannizzaro reaction?
(a) Ketones with no \( \alpha \)-hydrogen
(b) Aldehydes with \( \alpha \)-hydrogen
(c) Carboxylic acids with \( \alpha \)-hydrogen
(d) Aldehydes with no \( \alpha \)-hydrogen
Answer: (d) Aldehydes with no \( \alpha \)-hydrogen

Question. In Clemmensen reduction, carbonyl compound is treated with _________.
(a) zinc amalgam + HCl
(b) sodium amalgam + HCl
(c) zinc amalgam + nitric acid
(d) sodium amalgam + \( HNO_3 \)
Answer: (a) zinc amalgam + HCl

Question. The reagent which does not react with both, acetaldehyde and benzaldehyde.
(a) Sodium hydrogen sulphite
(b) Phenyl hydrazine
(c) Fehling’s solution
(d) Grignard reagent
Answer: (c) Fehling’s solution

Question. \( C_6H_5 – CO – CH_3 \xrightarrow{NaOH/I_2} ? + ? \)
(a) \( C_6H_5COOH + CH_4 \)
(b) \( C_6H_5COONa + CHI_3 \)
(c) \( C_6H_6 + CH_3COONa + HI \)
(d) \( C_6H_5CH_2COOH \)
Answer: (b) \( C_6H_5COONa + CHI_3 \)

Question. Predict the product of the following reaction:
\( CH_3 – C(=O) – CH_3 \xrightarrow[(ii) KOH/Glycol, \Delta]{(i) H_2N – NH_2} ? \)
(a) \( CH_3CH_2CH_3 \)
(b) \( CH_3CHOHCH_3 \)
(c) \( CH_3CH_2CHO \)
(d) \( CH_3CONHCH_3 \)
Answer: (a) \( CH_3CH_2CH_3 \)

Question. Formaldehyde reacts with methyl magnesium bromide followed by hydrolysis to form:
(a) Methanol
(b) Ethanol
(c) Propanol
(d) Butanol
Answer: (b) Ethanol

Question. Common name of Ethane-1,2-dioic acid is known as:
(a) Oxalic acid
(b) Phthalic acid
(c) Adipic acid
(d) Acetic acid
Answer: (a) Oxalic acid

Question. The carboxylic acid that does not undergo HVZ reaction is:
(a) \( CH_3COOH \)
(b) \( (CH_3)_2CHCOOH \)
(c) \( CH_3CH_2CH_2CH_2COOH \)
(d) \( (CH_3)_3CCOOH \)
Answer: (d) \( (CH_3)_3CCOOH \)

Question. Which of the following acids does not form anhydride?
(a) Formic acid
(b) Acetic acid
(c) Propionic acid
(d) n-butyric acid
Answer: (a) Formic acid

Question. Which of the following is the strongest acid?
(a) Acetic acid
(b) Phenol
(c) Methyl alcohol
(d) Water
Answer: (a) Acetic acid

Question. The reaction in which the aqueous solution of sodium salt of carboxylic acids on electrolysis give alkanes:
(a) Soda lime decarboxylation
(b) Kolbe’s electrolysis decarboxylation
(c) Dry distillation of calcium formate
(d) Reduction of carboxylic acid.
Answer: (b) Kolbe’s electrolysis decarboxylation

Assertion and Reason Based MCQs

Directions: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

Question. Assertion (A): Oxidation of ketones is easier than aldehydes.
Reason (R): C–C bond of ketones is stronger than C–H bond of aldehydes.
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (d) (A) is false, but (R) is true.

Question. Assertion (A): Benzaldehyde is less reactive than ethanal towards nucleophilic addition reactions.
Reason (R): Ethanal is more sterically hindered.
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).

Question. Assertion (A): Aromatic aldehydes and formaldehyde undergo Cannizzaro reaction.
Reason (R): Aromatic aldehydes are almost as reactive as formaldehyde.
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (c) (A) is true, but (R) is false.

Question. Assertion (A): Aldehydes and ketones, both react with Tollen’s reagent to form silver mirror.
Reason (R): Both aldehydes and ketones contain a carbonyl group.
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (d) (A) is false, but (R) is true.

Question. Assertion (A): Benzoic acid does not undergo Friedel-craft’s reaction.
Reason (R): The carboxyl group is activating group and undergo electrophilic substitution reaction.
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (c) (A) is true, but (R) is false.

Question. Assertion (A): Compounds containing —CHO group are easily oxidised to corresponding carboxylic acids.
Reason (R): Carboxylic acids can be reduced to alcohols by treatment with \( LiAlH_4 \).
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).

Question. Assertion (A): Aromatic carboxylic groups do not undergo Friedel- Crafts reaction.
Reason (R): Carboxyl group is deactivating and the catalyst aluminium chloride gets bonded to the carboxyl group.
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (a) Both (A) and (R) are true, and (R) is the correct explanation of (A).

Question. Assertion (A): Carboxylic acids are more acidic than phenols.
Reason (R): Phenols are ortho and para directing.
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Answer: (b) Both (A) and (R) are true, but (R) is NOT the correct explanation of (A)