See image — Aldehydes Ketones and Carboxylic Acids Chemistry Question

💡 Solution & Explanation

Concept: The reaction of a carbonyl compound (here acetone, a ketone) with HCN is a classic nucleophilic addition reaction. Step 1 - Identify the reaction type: At pH 9 to 10 (mildly basic conditions), HCN partially dissociates to provide CN⁻ (cyanide ion), which acts as a nucleophile. The CN⁻ attacks the electrophilic carbonyl carbon of acetone in a nucleophilic addition mechanism. Step 2 - Identify product (A): The CN⁻ adds to the carbonyl carbon, and after protonation, the product is acetone cyanohydrin: (CH3)2C(OH)(CN). This is a cyanohydrin, confirming option (a) is correct. Step 3 - Verify option (b): Since CN⁻ (a nucleophile) adds across the C=O double bond, this is indeed a nucleophilic addition reaction. Option (b) is correct. Step 4 - Verify option (c): Alkenes (C=C) are electron-rich and typically undergo electrophilic addition, not nucleophilic addition. The C=O bond is polarized (carbon is electrophilic) unlike the C=C bond, so alkenes do not react with HCN in the same nucleophilic addition manner. Option (c) is correct. Step 5 - Conclusion: Since options (a), (b), and (c) are all individually correct, option (d) 'All of these' is the answer. Therefore, the correct answer is D.