The action of nitrous acid on ethyl amine gives

Which of the following is expected to be the least basic?

In the following reaction,$X$ is:
$X$ $\xrightarrow{\text{Bromination}} Y$ $\xrightarrow{NaNO_2 + HCl} Z$ $\xrightarrow[C_2H_5OH]{\text{Boiling}} \text{1,3,5-Tribromobenzene}$

In the given reaction,what is the structure of the major product $X$?

Products that are formed in the given reaction including by-products are: $CH_3CH_2CH_2CH_2CONH_2 + Br_2 + 4 NaOH \rightarrow$

Which of the following is the strongest base?