Question

Formation of cyanohydrin from a ketone is an example of

• A. electrophilic addition
• B. nucleophilic addition
• C. nucleophilic substitution
• D. electrophilic substitution

Hint:

Carbonyl compounds undergo nucleophilic addition because carbonyl carbon is electrophilic. Cyanohydrin formation is a standard nucleophilic addition reaction.

Answer 1

The Correct Option is B

Step 1: Reaction involved.
Ketone reacts with HCN to form cyanohydrin:
\[ R_2C=O + HCN \rightarrow R_2C(OH)CN \] Step 2: Identify attacking species.
In this reaction, \(CN^-\) attacks the carbonyl carbon.
Carbonyl carbon is electrophilic due to polar \(C=O\) bond.
Step 3: Type of reaction.
Since a nucleophile \(CN^-\) adds to carbonyl carbon, this is nucleophilic addition.
Final Answer: \[ \boxed{\text{nucleophilic addition}} \]