What is formed when benzoyl chloride reacts with aniline in the presence of sodium hydroxide?

The main product of the following reaction will be:

Fluorination of an aromatic ring is easily accomplished by treating a diazonium salt with $HBF_4$. Which of the following conditions is correct about this reaction?

What is formed when $1-$propanamine is treated with $NaNO_2$ and $HCl$?

In the above conversion of compound $(X)$ to product $(Y)$,the sequence of reagents to be used will be:

Which isomeric amine has the lowest boiling point?