$A$ $(C_{4}H_{8}Cl_{2})$ $\xrightarrow{\text{Hydrolysis at } 373 \text{ K}}$ $B$ $(C_{4}H_{8}O)$
$B$ reacts with hydroxylamine but does not give Tollen's test. Identify $A$ and $B$.

Predict the product of the following reaction:
(Image: $A$ chiral carbon attached to a phenyl ring with a para-chloro group,a deuterium atom $(D)$,a hydrogen atom $(H)$,and a chlorine atom (Cl) in a specific stereochemical configuration. The reaction is with $NaI$ in acetone.)

Given below are two statements:
Statement $(I)$: Benzyl chloride reacts faster in $S_N1$ mechanism than ethyl chloride.
Statement $(II)$: Ethyl carbocation intermediate is less stabilized by hyperconjugation than benzyl carbocation by resonance.
In the light of the above statements, choose the correct answer from the options given below:

From each of the following pairs,select the compound that will react faster with sodium iodide in acetone:
Pair-$A$: $(1) \, 2-$Chloropropane,$(2) \, 2-$Bromopropane
Pair-$B$: $(3) \, 1-$Bromobutane,$(4) \, 2-$Bromobutane

The correct sequence of reagents for the conversion of $X$ to $Y$ is :

Which of the following expressions is representative of the rate law for a $S_{N}2$ reaction?