Question

Consider the following reactions & identify A, X, Y & Z

• A. A-Methoxymethane, X-Ethanol, Y-Ethanoic acid, Z -Semicarbazide
• B. A-Ethanal, X-Ethanol, Y-But-2-enal, Z -Semicarbazone
• C. A-Ethanol, X-Acetaldehyde, Y-Butanone, Z-Hydrazone
• D. A-Methoxymethane, X-Ethanoic acid, Y-Acetate ion, Z-Hydrazine

Answer 1

The correct option is B

A-Ethanal, X-Ethanol, Y-But-2-enal, Z -Semicarbazone

$C_2{H}_{6}O$ could be dimethyl ether, ethylene oxide or ethanol. But the reaction with Cu at 573 K all but confirms that the substrate is in fact, ethanol $C_2{H}_{5}OH$, which gets oxidized by cupper dust to ethanol. So A is ethanal (A), which shows a positive Tollen’s reagent test.

A - acetaldehyde, undergoes aldol condensation to yield but-2-enal - the $\alpha -\beta$ unsaturated aldehyde. Also, A reacts with semicarbazide to give an imine called - semicarbazone (this is not a specific compound, it is a class of imine).