Which type of nucelophillic substitution mechanism involved to obtained compound $\left(z\right)$ from compound $\left(x\right)$. Write the name of mechanism?

Q. (i) $C{H}_2-Br+KOH\to C{H}_{3}OH+KBr$
Write types of nucelophillic substitution reaction in the above reaction (i) and (ii)?
(b) Write two differences between mechanism of reaction (i) and (ii)?

Q. Which one of the following compounds most readily undergoes substitution by $S_{N}2$ mechanism?

Q. Which of the following steps is not involved in the general mechanism of an electrophillic substitution of benzene?

Q. Write the names of process to obtain compound $\left(y\right)$ and compound $\left(z\right)$ from compound $\left(x\right)$ in above nucleophilic reaction (i) and (ii)?

Q. Write the electrophilic substitution reaction mechanism for benzene with an example.