Which factor is effective in the preparation of alcohol from alkene using $Al_2O_3$?

Which reagent is used to prepare alcohol from alkyl halide?

$RMgBr$ on reaction with an excess of oxygen followed by hydrolysis gives:

Show how will you synthesize:
$(i)$ $1-$phenylethanol from a suitable alkene.
$(ii)$ cyclohexylmethanol using an alkyl halide by an $S_{N}2$ reaction.
$(iii)$ pentan$-1-$ol using a suitable alkyl halide?

Explain the preparation of alcohols by acid-catalyzed hydration of alkenes with its mechanism.

Heating of $2-$chloro$-1-$phenylbutane with $EtOK/EtOH$ gives $X$ as the major product. Reaction of $X$ with $Hg(OAc)_2/H_2O$ followed by $NaBH_4$ gives $Y$ as the major product. $Y$ is