Arrange the following halides in decreasing order of $S_N1$ reactivity:
$(I)$ $CH_3CH_2CH_2Cl$
$(II)$ $CH_2=CHCHClCH_3$
$(III)$ $CH_3CH_2CHClCH_3$

The major product obtained in the following reaction is $C_2H_5ONa + (CH_3)_3C-Cl \rightarrow$

Consider the given reaction: $CH_3-CH=CH-CH_2-OH \xrightarrow[S_N1]{HBr} [P]$. In the given reaction,the product $[P]$ is:

At $30\,^\circ C$,the rate of reaction between $2$-bromobutane and $OH^-$ in $75\%$ ethanol and $25\%$ water is given by: $\text{Rate} = 3.20 \times 10^{-5} [2\text{-bromobutane}][OH^-] + 1.5 \times 10^{-6} [2\text{-bromobutane}]$. If $[OH^-] = 1.0\,M$,what percentage of the reaction proceeds via the $S_N2$ mechanism?

The organic halide,which does not undergo hydrolysis by $S_{N}1$ mechanism is

$A$ dihalogen derivative $X$ of a three-carbon hydrocarbon reacts with alcoholic $KOH$ to give another hydrocarbon,which gives a red precipitate with ammoniacal $Cu_2Cl_2$. Reaction of $X$ with aqueous $KOH$ gives an aldehyde. The compound $X$ is .......