The aldol condensation of acetaldehyde results in the formation of:

Propanal, on reaction with dilute $\mathrm{NaOH}$ forms:

The base-catalysed aldol condensation will not occur with which of the following:

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

Acetaldehyde and acetone can be distinguished by:

Which of the following is incorrect?

Acetaldehyde reacts with semicarbazide and forms semicarbazone. Its structure is:

The cyanohydrin of a compound on hydrolysis, gives an optically active $\mathrm{\alpha }$-hydroxy acid. The compound is:

Phenylmethyl ketone can be converted into ethylbezene in one step by which of the following reagents?