See image — Aldehydes Ketones and Carboxylic Acids Chemistry Question

💡 Solution & Explanation

Step 1: Identify compound (A). Benzene reacts with formaldehyde (HCHO) in the presence of 2HCl via a chloromethylation-type reaction (actually a Blanc reaction / chloromethylation). Benzene + HCHO + 2HCl yields benzyl chloride (Ph-CH2-Cl) as compound (A). This is the classic chloromethylation of benzene (Blanc chloromethylation), where the benzene ring reacts with formaldehyde and HCl to give benzyl chloride. Step 2: Identify compound (B). Benzyl chloride (Ph-CH2-Cl) reacts with AgNO2. When an alkyl halide reacts with AgNO2 (silver nitrite), the reaction proceeds via an SN2 mechanism where the nitrite ion acts as a nucleophile through its nitrogen atom (ambident nucleophile). AgNO2 is known to give the nitroalkane product (C-nitro compound) as the major product because the silver ion helps ionize the halide and the free nitrite anion attacks through nitrogen. Therefore, Ph-CH2-Cl + AgNO2 -> Ph-CH2-NO2 (phenylnitromethane) + AgCl. Step 3: Contrast with KNO2. If KNO2 were used instead, the reaction would give predominantly the nitrite ester (Ph-CH2-ONO) because in solution with K+ the nitrite attacks through oxygen. But AgNO2 gives the C-nitro product. Step 4: Eliminate other options. Option (b) Ph-CH2-ONO would be the product with KNO2, not AgNO2. Option (c) Ph-CHO (benzaldehyde) is not formed in this reaction sequence. Option (d) Ph-O-N=O is a phenyl nitrite, which is irrelevant here. Therefore, the correct answer is A.