Select the compound which on treatment with nitrous acid liberates nitrogen.

The chemical reaction shown in the image represents the reduction of a diazonium salt to an aromatic hydrocarbon. Identify the reagent typically used for this transformation.

Which of the following statements is $NOT$ correct?

Given below are two statements:
Statement $I$: Aniline does not undergo Friedel-Crafts alkylation reaction.
Statement $II$: Aniline cannot be prepared through Gabriel synthesis.
In the light of the above statements,choose the correct answer from the options given below:

Which of the following is the incorrect order?

In the reactions given below,
$R-Cl \xrightarrow{(i)\, KCN, (ii)\, LiAlH_4}$ Product $A$
$R-Cl \xrightarrow{(i)\, AgCN, (ii)\, LiAlH_4}$ Product $B$
the compounds $A$ and $B$ are