For a given alkyl group,the densities of the halides follow the order:

For the following reactions:
$CH_{3}CH_{2}CH_{2}Br + Z^{-} \xrightarrow[substitution]{k_s} CH_{3}CH_{2}CH_{2}Z + Br^{-}$
$CH_{3}CH_{2}CH_{2}Br + Z^{-} \xrightarrow[elimination]{k_e} CH_{3}CH=CH_{2} + HZ + Br^{-}$
where
$Z^{-} = CH_{3}CH_{2}O^{-} (A)$ or $(CH_{3})_{3}CO^{-} (B)$
$k_s$ and $k_e$ are,respectively,the rate constants for the substitution and elimination,and $\mu = \frac{k_s}{k_e}$,the correct option is:

For $CH_3Br + OH^{-} \rightarrow CH_3OH + Br^{-}$ the rate of reaction is given by the expression:

The ease of dehydrohalogenation of alkyl halide with alcoholic $KOH$ is:

$KCN$ reacts readily to give a cyanide with:

Which one of the following is likely to give a precipitate with $AgNO_3$ solution?