Non-occurrence of the following reaction
$Br^{-} + CH_3OH \rightarrow BrCH_3 + OH^{-}$,is due to

On monochlorination of $2-$methylbutane,the total number of chiral compounds is

The reactivity of $2-$bromo$-2-$methylbutane $(I)$,$1-$bromopentane $(II)$ and $2-$bromopentane $(III)$ towards $S_N2$ displacement is such that :

The correct decreasing order of $SN^2$ reactivity of the following alkyl halides is:
$(I)$ $CH_2=CH-Br$
$(II)$ $CH_3-Br$
$(III)$ $CH_3-CH(Br)-CH_3$
$(IV)$ $CH_3-CH_2-Br$

What is the correct order of leaving group ability for the following groups?
$I. -OAc$
$II. -OMe$
$III. -OSO_2Me$
$IV. -OSO_2CF_3$

Match the following reactants with their corresponding products:
Reactants:
$(A)$ $C_2H_5Cl$,moist $Ag_2O$
$(B)$ $C_2H_5Cl$,ethanolic $AgCN$
$(C)$ $C_2H_5Cl$,ethanolic $AgNO_2$
$(D)$ $C_2H_5Cl$,ethanolic $KOH$
Products:
$(i)$ $CH_3CH_2ONO$
$(ii)$ $C_2H_4$
$(iii)$ $CH_3CH_2OH$
$(iv)$ $CH_3CH_2NC$
Select the correct match: