Question

Aldehydes and ketones will not form crystalline derivatives with

• A. sodium bisulphite
• B. phenyl hydrazine
• C. semicarbazide hydrochloride
• D. dihydrogen sodium phosphate

Answer 1

Answer: (D)

dihydrogen sodium phosphate

Answer 2

Dihydrogen sodium phosphate $(NaH_2 PO_4)$ does not react with aldehydes and ketones because $(NaH_2 PO_4)$ does not have any lone pair of electron on phosphorus atom, so it cannot act as a nucleophile.