The major product of the following reaction is

An optically active alkyl halide $C_4H_9Br$ $[A]$ reacts with hot $KOH$ dissolved in ethanol and forms alkene $[B]$ as the major product,which reacts with bromine to give dibromide $[C].$ The compound $[C]$ is converted into a gas $[D]$ upon reacting with alcoholic $NaNH_2.$ During hydration,$18 \ g$ of water is added to $1 \ mole$ of gas $[D]$ on warming with mercuric sulphate and dilute acid at $333 \ K$ to form compound $[E].$ The $IUPAC$ name of compound $[E]$ is $:$

The reaction of hydrazine $(NH_2NH_2)$ with aldehydes and ketones yields a compound with the general structure:

What will be the compound $X$ in the given reaction?
$MeO-C_6H_4-CHO + (X) \xrightarrow{CH_3COONa, H_3O^+} MeO-C_6H_4-CH=CHCOOH$

The product formed by the reaction of chlorine with benzaldehyde in the absence of a catalyst is

Both ethanal and propanone will react with which of the following?