$(i)$ Ionizes phenol to make more reactive phenoxide ion
$(ii)$ Increases electrophilicity of bromine.
$C{H_2} = C{H_2}\, \xrightarrow{{HOCl}} \,A\xrightarrow{{_R}}\begin{array}{*{20}{c}}
{C{H_2}OH} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_2}OH}
\end{array}$
ઇથેનોલ $\xrightarrow{{PB{r_3}}}X\,\xrightarrow{{alc.\,KOH}}\,Y$$\,\xrightarrow[{(ii)\,{H_2}O\,,\,heat}]{{(i)\,{H_2}S{O_4},\,room\,\,temperature}}Z$
નીપજ $Z$ શું હશે ?