NEET UG CHEMISTRY Multiple Choice Questions (MCQs)

236. Which of the following is a characteristic reaction of alcohols?

a) Nucleophilic addition

b) Electrophilic substitution

c) Dehydration to form alkene

d) Acidic hydrolysis

Answer: c) Dehydration to form alkene

237. Which reagent is used to distinguish between primary, secondary, and tertiary alcohols?

a) Sodium metal

b) Lucas reagent

c) Bromine water

d) Potassium permanganate

Answer: b) Lucas reagent

238. Which of the following alcohols will show the fastest reaction with Lucas reagent?

a) Methanol (Primary alcohol)

b) Ethanol (Secondary alcohol)

c) Tert-butyl alcohol (Tertiary alcohol)

d) Propanol (Primary alcohol)

Answer: c) Tert-butyl alcohol (Tertiary alcohol)

239. Which of the following is a property of phenols?

a) Phenols are weakly acidic

b) Phenols are neutral in nature

c) Phenols show basicity

d) Phenols have no reaction with bromine water

Answer: a) Phenols are weakly acidic

240. Which of the following reactions is characteristic of phenols?

a) Dehydration

b) Nitration

c) Oxidation

d) Aldol condensation

Answer: b) Nitration

241. What is the product of the Reimer-Tiemann reaction?

a) Salicylic acid

b) Phenol

c) Benzoquinone

d) Hydroquinone

Answer: a) Salicylic acid

242. Which of the following is the structure of an ether?

a) R-O-R'

b) R-C=O

c) R-OH

d) R-COOH

Answer: a) R-O-R'

243. Which of the following is true about the reactivity of aldehydes and ketones?

a) Aldehydes are more reactive than ketones

b) Ketones are more reactive than aldehydes

c) Aldehydes and ketones have the same reactivity

d) Aldehydes and ketones do not undergo nucleophilic addition

Answer: a) Aldehydes are more reactive than ketones

244. What is the product of the reaction of an aldehyde with HCN?

a) Hydration product

b) Cyanohydrin

c) Alcohol

d) Aldol product

Answer: b) Cyanohydrin

245. Which of the following reagents is used in the reduction of aldehydes and ketones?

a) Grignard reagent

b) Sodium borohydride

c) Sodium hydroxide

d) Bromine water

Answer: b) Sodium borohydride

246. Which of the following reactions occurs when an aldehyde undergoes oxidation?

a) Cannizzaro reaction

b) Aldol condensation

c) Formation of a carboxylic acid

d) Haloform reaction

Answer: c) Formation of a carboxylic acid

247. What is the product of the Cannizzaro reaction?

a) Alcohol

b) Aldehyde

c) Carboxylate salt and alcohol

d) Carboxylic acid and alcohol

Answer: c) Carboxylate salt and alcohol

248. Which of the following is the best method to distinguish between aldehydes and ketones?

a) Fehling’s test

b) Tollen’s test

c) Both Fehling’s and Tollen’s tests

d) Lucas test

Answer: c) Both Fehling’s and Tollen’s tests

249. Which of the following factors affects the acidic strength of carboxylic acids?

a) The inductive effect of substituents

b) The number of carbon atoms

c) The size of the functional group

d) The nature of the alkyl group

Answer: a) The inductive effect of substituents

250. Which of the following methods is used for the preparation of aldehydes?

a) Reduction of esters

b) Oxidation of alcohols

c) Hydrolysis of nitriles

d) Reduction of carboxylic acids

Answer: b) Oxidation of alcohols