Free Aldehydes and Ketones MCQs with Answers

• A. They have higher boiling points than that of alkalies
• B. They have lower boiling points than that of alcohols
• C. Aldehydes are present in essential oils and ketonic group is presentin camphor
• D. Aldehydes have H-bonding but ketones do not have

Explanation: Statement of option d is incorrect. Aldehydes and ketones both can show H-bonding.

• A. Glucose and fructose
• B. Glucose and maltose
• C. Propanone and benzaldehyde
• D. Hydroxypropanone and benzaldehyde

Explanation: Option A is correct. Glucose and fructose are both reducing sugars, which can be distinguished by Fehling's solution.

• A. C2H5COCH3
• B. C2H5CH(CH3)OH
• C. CH3COCH3
• D. C2H5CH2CHO

Explanation: When HCN reacts with a ketone, two new bonds form. The H from HCN adds to 0 in C=O to form C-OH bond and -CN adds to C to form C- CN bond.

• A. Carbonyl carbon contains no lone pair
• B. Carbonyl oxygen contains two lone pair
• C. Carbonyl group contains two lone pairs
• D. All of these

Explanation: A) Carbonyl carbon contains no lone pair: A carbonyl group consists of a carbon atom double-bonded to an oxygen atom (C=O).

• A. Solidification.
• B. Chromatography.
• C. Re-distillation.
• D. Steam distillation.

Explanation: The answer is: Re-distillation. During the oxidation of ethanol to get an acetaldehyde, acetaldehyde is immediately distilled off to avoid…

• A. The addition product formed with propene would not be stable
• B. Propanone is more susceptible to nucleophilic attack than propene
• C. Propanone is more susceptible to electrophilic attack than propene
• D. Propanone is more susceptible to free radical attack than propene

Explanation: Option B is correct.Propanone is more susceptible to nucleophilic attack than propene.

• A. Methanol
• B. Methanoic acid
• C. Acetone
• D. Acet Aldehyde

Explanation: Aldehydes on oxidation give carboxylic acids. As methanoic acid is carboxylic acid, so, option B is correct.

• A. Calcium acetate
• B. Calcium formate
• C. Ethyl acetate
• D. Acetic Acid

Explanation: Acetone is prepared by dry distillation of calcium acetate.Hence, option A is correct.

• A. Formic acid
• B. Ethanoic acid
• C. Propanoic Acid
• D. Butyric Acid

Explanation: Ketones on oxidation give carboxylic acids with 1 carbon atom less than ketone.

• A. o-nitro toluene
• B. p-nitro toluene
• C. m-nitro toluene
• D. Benzoic acid

Explanation: When toluene is subjected to oxidation, only the methyl group undergoes oxidation while the benzene ring remains intact.

• A. Acetylene
• B. Phenol
• C. Toluene
• D. Benzene

Explanation: Beneze is oxidized in presence of vanadium peroxide (V2O5) producing maleic anhydride.STB Pg- 157Hence, option D is correct.

• A. Nucleophile and electrophile
• B. Base and nucleophile
• C. Electrophile and nucleophile
• D. Nucleophile and base

Explanation: In the Aldol condensation, NaOH acts as a base by accepting a proton, and in the Cannizaro's reaction, it acts as a nucleophile by…

• A. K2Cr2O7
• B. H2SO4
• C. KMnO4
• D. HCI

Explanation: Aldehydes are not easily oxidized by hydrochloric acid (HCl), as it's not a effective oxidizing agent for aldehydes.

• A. 2.4 - DNPH test
• B. Tollen's Test
• C. Sodium Nitro Prusside Test
• D. Fehling's Solution

Explanation: Aldehydes typically do not react with sodium nitroprusside, which is a test for the detection of ketones.

• A. 1,3-Diisopropylpropan-2-on
• B. 2,4-Dimethylpentan-3-one
• C. 2,4-Dimethylpentan-2-one
• D. 1,3-Dimethylpropan-2-one

Explanation: 2,4-Dimethylpentan-3-oneExplanation:Diisopropyl ketone refers to a ketone with two isopropyl groups attached to the carbonyl carbon.The…

• A. A ketone
• B. An aldehyde
• C. An acid
• D. An alcohol

Explanation: Aldehyde (Correct)Explanation: Aldehydes reduce Tollens' reagent (Ag⁺) to metallic silver, creating a silver mirror on the test tube.

• A. Clemmensen reduction
• B. Williamson's synthesis
• C. Wolf-Kishner reduction
• D. Dow process

Explanation: Clemmensen reduction is a chemical reaction described as a reduction of ketones or aldehydes to alkanes using zinc amalgam and…

• A. Hydrazine
• B. Hydrazone
• C. Oxime
• D. Imine

Explanation: When aldehydes and ketones react with hydroxylamine (NH₂OH), they form a class of compounds known as oximes.

• A. Reduction of aldehydes
• B. Oxidation of Copper(II)
• C. Oxidation of aldehyde
• D. Oxidation of Ketone

Explanation: Fehling's solution is specifically designed to test for aldehydes, which are oxidized to carboxylic acids during the reaction.

• A. Nucleophilic Addition Reactions
• B. Reduction to Alcohols
• C. Formation of Hydrazones
• D. Reaction with Fehling's Solution

Explanation: Fehling's solution is used to test for the presence of reducing sugars and aldehydes.