How will you carry out the following conversions?
$(i)$ Toluene $\to$ $p$-toluidine
$(ii)$ $p$-Toluidine diazonium chloride $\to$ $p$-toluic acid

(N/A) $(i)$ Toluene $\to$ $p$-toluidine:
First,toluene undergoes nitration with concentrated $HNO_3$ and $H_2SO_4$ to form $p$-nitrotoluene. Then,$p$-nitrotoluene is reduced using $Fe/HCl$ to yield $p$-toluidine.
$(ii)$ $p$-Toluidine diazonium chloride $\to$ $p$-toluic acid:
First,$p$-toluidine diazonium chloride reacts with $CuCN/KCN$ (Sandmeyer reaction) to form $p$-tolunitrile ($p$-methylbenzonitrile). Subsequently,the nitrile group is hydrolyzed with $H_2O/H^+$ to produce $p$-toluic acid.