A compound (X) on hydrolysis gave an acid and alcohol. Acid gave violet colour with neutral $\mathrm{F}\mathrm{e}\mathrm{C}{\mathrm{l}}_3$ while alcohol gave yellow precipitate on boiling with ${\mathrm{I}}_2$ and $\mathrm{N}\mathrm{a}\mathrm{O}\mathrm{H}$ . X can be

Which is the most suitable reagent for the following transformation?

Write mechanism of the following reaction :

${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}\underset{443 \mathrm{K}}{\overset{{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }}{\mathrm{CH}}_2={\mathrm{CH}}_2+{\mathrm{H}}_2\mathrm{O}$

The major product of the following reaction is