Addition of $KI$ accelerates the hydrolysis of primary alkyl halides because

What is the product formed when $Ethyl \ bromide$ reacts with alcoholic $Silver \ nitrite$ $(AgNO_2)$?

Monohalides on reacting with alcoholic $KOH$ give

Which of the following is the correct order of decreasing $S_{N^{2}}$ reactivity?
($X$ is a halogen)

The order of reactivity of the compounds $C_6H_5CH_2Br$,$C_6H_5CH(C_6H_5)Br$,$C_6H_5CH(CH_3)Br$ and $C_6H_5C(CH_3)(C_6H_5)Br$ in $S_N2$ reaction is

Consider the following reactions:
$(a) \; (CH_3)_3CCH(OH)CH_3 \xrightarrow{conc. H_2SO_4} $
$(b) \; (CH_3)_2CHCH(Br)CH_3 \xrightarrow{alc. KOH} $
$(c) \; (CH_3)_2CHCH(Br)CH_3 \xrightarrow{(CH_3)_3CO^{-}K^{+}} $
$(d) \; (CH_3)_2C(OH)CH_2CHO \xrightarrow{\Delta} $
Which of these reaction$(s)$ will not produce Saytzeff product?