Haloalkanes in the presence of alcoholic $KOH$ undergo:

The correct order for increasing reactivity towards $S_N1$ substitution for the following compounds is:
$1. CH_3CH_2Br$
$2. CH_2=CHCH(Br)CH_3$
$3. CH_2=CHBr$
$4. CH_3CH(Br)CH_3$

What is the major product obtained in the reaction of $1-$phenyl$-2-$bromobutane with $NaOMe$?

Which of the following species is most reactive in $S_{N}2$ reaction?

What is the major product obtained in the following reaction?

Which of the compounds will react faster in an $S_N1$ reaction?
$CH_3-CH_2-Cl$ and $C_6H_5-CH_2-Cl$