Acetone is treated with an excess of ethanol in the presence of hydrochloric acid. The product obtained is:

Consider the following reaction: 

$\underset{\mathrm{Pd}-{\mathrm{BaSO}}_4}{\overset{{\mathrm{H}}_2}{\to }}+\text{'}{\mathrm{A}}^{\text{'}}$

Consider the reaction: 

$\mathrm{RCHO}+{\mathrm{NH}}_2{\mathrm{NH}}_2\to \mathrm{RCH}=\mathrm{N}-{\mathrm{NH}}_2$ What sort of reaction is it?

Reaction of a carbonyl compound with one of the following reagents involves nucleophilic addition followed by elimination of water. The reagent is _____.