Assertion & Reason Test: Aldehydes, Ketones & Carboxylic Acids


10 Questions MCQ Test Topic-wise MCQ Tests for NEET | Assertion & Reason Test: Aldehydes, Ketones & Carboxylic Acids


Description
Attempt Assertion & Reason Test: Aldehydes, Ketones & Carboxylic Acids | 10 questions in 20 minutes | Mock test for NEET preparation | Free important questions MCQ to study Topic-wise MCQ Tests for NEET for NEET Exam | Download free PDF with solutions
QUESTION: 1

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Oxidation of ketones is easier than aldehydes.

Reason (R): C–C bond of ketones is stronger than C–H bond of aldehydes.

Solution: Oxidation of aldehydes are easier than ketones.
QUESTION: 2

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Aromatic aldehydes and formaldehyde undergo Cannizzaro reaction.

Reason (R): Aromatic aldehydes are almost as reactive as formaldehyde.

Solution: Aromatic aldehydes and formaldehyde do not contain α-hydrogen and thus undergo Cannizzaro reaction. Formaldehyde is more reactive than aromatic aldehydes.
QUESTION: 3

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Benzoic acid does not undergo Friedel-craft’s reaction.

Reaction (R): The carboxyl group is activating and undergo electrophilic substitution reaction.

Solution: The carboxyl group (-COOH) is deactivating group because it is electron with drawing group. It decreases the electron density at benzene ring, hence deactivates it towards electrophilic substitution reactions.
QUESTION: 4

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

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.

Solution: Aromatic carboxylic groups do not undergo Friedel-Crafts reaction because Carboxyl group is deactivating and the catalyst aluminium chloride gets bonded to the carboxyl group.
QUESTION: 5

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Benzaldehyde is less reactive than ethanal towards nucleophilic addition reactions.

Reason (R): Ethanal is more sterically hindered.

Solution: The carbon atom of the carbonyl group of benzaldehyde is less electrophilic than carbon atom of carbonyl group present in ethanal. The polarity of the carbonyl group is reduced in benzaldehyde due to resonance hence it is less reactive than ethanal towards nucleophilic addition reaction.
QUESTION: 6

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

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.

Solution: Both aldehydes and ketones have carbonyl group but only aldehydes react with Tollens' reagent to give silver mirror.
QUESTION: 7

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

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 LiAlH4.

Solution: Compounds containing —CHO group are easily oxidised to corresponding carboxylic acids.
QUESTION: 8

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Carboxylic acids are more acidic than phenols.

Reason (R): Phenols are ortho and para directing.

Solution: Carboxylic acids are more acidic than phenols as the carboxylate ion, the conjugate base of carboxylic acid is stabilized by two equivalent resonance structures. Thus, the negative charge is delocalized effectively. However, in phenols, negative charge is less effectively delocalized over oxygen atom and carbon atoms in phenoxide ion.

QUESTION: 9

Directions: These questions consist of two statements, each printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses.

Assertion : The boiling points of aldehydes and ketones are higher than hydrocarbons and ethers of comparable molecular masses.

Reason : There is a weak molecular association in aldehydes and ketones arising out of the dipole-dipole interactions.

Solution: Boiling points of Aldehydes and ketones are higher than their corresponding hydrocarbons or Ethers.

Because Aldehydes and ketones are more polar than Ethers therefore intermolecular dipole-dipole attraction is stronger.

And hydrocarbons only have weak Van der Waal forces.

QUESTION: 10

Directions: These questions consist of two statements, each printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses.

Assertion : Compounds containing –CHO group are easily oxidised to corresponding carboxylic acids.

Reason : Carboxylic acids can be reduced to alcohols by treatment with LiAlH4

Solution: Due to high electronegativity of oxygen, carbonyl groups in aldehydes are a strong electron-withdrawing group. This weakens the C-H bond in aldehydes. Even a weak oxidizing agent can oxidize the aldehydes into the corresponding carboxylic acids.
Use Code STAYHOME200 and get INR 200 additional OFF
Use Coupon Code