Write the equation for the following reaction:

Salicylic acid is treated with acetic anhydride in the presence of conc.${\mathrm{H}}_2{\mathrm{SO}}_4$

Write the equations for the following reaction:

Tertiary butyl chloride is treated with sodium ethoxide.

Give equation of the following reaction:

Treating phenol with chloroform in presence of aqueous $\mathrm{NaOH}$.

Give reasons for the following observation:

Aniline is acetylated before nitration reaction.

Give reasons for the following observation:

$\mathrm{pKb}$ of aniline is lower than the m-nitroaniline.

Give reasons for the following observation:

Primary amine on treatment with benzenesulphonyl chloride forms a product which is soluble in $\mathrm{NaOH}$ however secondary amine gives product which is insoluble in $\mathrm{NaOH}$.