$+HCl$

$a=$ Proton transfer

e $=$ Electrophilic addition

$h=S_{N}1$ Nucleophilic substitution

b $=$ Lewis acid$/$base

$f=$ E$1$ Elimination

i $=S_{N}2$ Nucleophilic substitution

c $=$ Radical chain substitution

$g=E2$ Elimination

j $=$ Electrophilic aromatic substitution

d $=$ Radical chain addition

Identify the mechanism by which each of the reactions above proceeds from among the mechanisms listed. Use the letters a $-$ j for your answers.

$1$

$2.$