Free Nucleophilic Addition Reactions MCQs with Answers
35 Nucleophilic Addition Reactions MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Nucleophilic addition occurs at the polar carbonyl group of aldehydes and ketones, where a nucleophile attacks the electron-deficient carbon atom. Reactions with hydrogen cyanide, sodium bisulfite, alcohols and Grignard reagents are explained through tetrahedral intermediates, acid or base catalysis, and the different reactivity of aldehydes and ketones.
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35 questions · page 2 of 2
- A. Acid.
- B. Base.
- C. Water.
- D. Both acid and base.
Explanation: Nucleophilic addition reactions of carbonyl compounds involve the addition of a nucleophile (an electron-rich species) to the carbon atom…
Correct answer: Both acid and base.- A. Elimination+ addition
- B. Elimination+ Substitution
- C. Addition + substitution
- D. None of these
Explanation: Condensation involves elimination and addition. It is a reaction in which a water molecule is produced as a by-product.
Correct answer: Elimination+ addition23. In the addition of sodium bisulfite to carbonyl system, which of the following is a nucleophile?
- A. Sulphide ion
- B. Sulfite ion
- C. Hydride ion
- D. Sodium ion
Explanation: The addition of sodium bisulfite to a carbonyl group takes place as follows:Sodium bisulfite ionizes to form sulfite ions.The sulfite ion…
Correct answer: Sulfite ion- A. Hydroxyl ion
- B. Carbocation
- C. Carbanion
- D. Water
Explanation: The reaction mechanism below shows that the carbanion is the nucleophile of the reaction:
Correct answer: Carbanion- A. Carbanion
- B. Carbocation
- C. Carbene
- D. Alkoxide ion
Explanation: During the reduction of aldehydes with NaBH4, the "alkoxide ion" is seen as the intermediate formed hence the answer is D.
Correct answer: Alkoxide ion- A. Propane
- B. Butane
- C. Methane
- D. Ethane
Explanation: Explanation:The reaction is a typical Grignard reagent hydrolysis reaction where the Grignard reagent (CH3CH2MgBr) reacts with water to…
Correct answer: Ethane- A. Nucleophilic addition
- B. Electrophilic addition
- C. Electrophilic substitution
- D. Nucleophilic substitution
Explanation: It is an example of nucleophilic addition. The CN- ion has a negative charge and it is attracted to a positive charge so CN- is a…
Correct answer: Nucleophilic addition- A. Nucleophilic addition
- B. Nucleophilic substitution
- C. Electrophilic addition
- D. Addition elimination
Explanation: This reaction is called an addition-elimination reaction since a water molecule is eliminated from the reaction whereas the lone pair of…
Correct answer: Addition elimination- A. CH3OH
- B. C2H5OH
- C. (CH3)2CHOH
- D. ....
Explanation: When a Grignard reagent reacts with aldehydes and ketones, it results in production of addition products which on hydrolysis gives…
Correct answer: C2H5OH- A. Alcohol and aldehyde functional groups
- B. Alcohol and ether functional groups
- C. Aldehyde and ether functional groups
- D. Alcohol and carboxylic acid functional groups
Explanation: Hemiacetal is a molecule made up of a core carbon atom connected to four groups: -OR, -OH, -R, and -H.
Correct answer: Alcohol and ether functional groups- A. CH3CH2OH
- B. CH3CH2CHO
- C. CH3CH(OH)CH2CH3
- D. CH3CH2CH2OH
Explanation: The correct answer is CH3CH(OH)CH2CH3. In this Grignard reaction, the ethyl group from the Grignard reagent (CH3CH2MgBr) adds to the…
Correct answer: CH3CH(OH)CH2CH3- A. A compound formed by the reaction of an aldehyde with hydrazine.
- B. A compound formed by the reaction of an aldehyde with water.
- C. A compound formed by the reaction of an aldehyde with an amine.
- D. A compound formed by the reaction of an aldehyde with hydrogen cyanide.
Explanation: Aldehyde hydrazones are organic compounds derived from the reaction of aldehydes with hydrazine (NH2-NH2) or its derivatives.
Correct answer: A compound formed by the reaction of an aldehyde with hydrazine.- A. Electrophilic addition reaction
- B. Substitution reaction
- C. Nucleophilic addition reaction
- D. None of these
Explanation: So, when aldehydes undergo nucleophilic addition reactions, it means that a nucleophile (a species with a lone pair of electrons) attacks…
Correct answer: Nucleophilic addition reaction- A. Aldehyde
- B. Ketone
- C. Acid halide
- D. Carboxylic acid
Explanation: Grignard's reagent (RMgX) reacts with ketones to produce tertiary alcohols.
Correct answer: Ketone- A. To act as strong acid
- B. To act as nucleophile and add to carbonyl compounds
- C. To act as electrophile
- D. To catalyze hydrogenation reaction
Explanation: Grignard reagents are highly reactive nucleophiles that add to carbonyl compounds such as aldehydes and ketones to form addition products.
Correct answer: To act as nucleophile and add to carbonyl compounds