When ethyl chloride and alcoholic $KOH$ are heated,the compound obtained is

$A$ halogen compound $X$ $(C_4 H_9 Br)$ on hydrolysis gives an alcohol $Y$. The alcohol $Y$ undergoes dehydration with $20 \% H_3 PO_4$ at $358 \ K$. What is $X$?

In the given pair of compounds,in which pair is the second compound more reactive than the first toward $S_N2$ reaction?

Compound $(A), \, C_8H_9Br,$ gives a white precipitate when warmed with alcoholic $AgNO_3.$ Oxidation of $(A)$ gives an acid $(B), \, C_8H_6O_4.$ $(B)$ easily forms anhydride on heating. Identify the compound $(A).$

Identify the final product $[D]$ obtained in the following sequence of reactions.

The rate-limiting step of an $S_N1$ reaction follows the sequence shown below. Based on the assumption that $R$ contains $3$ different groups,which statement is true?
$\mathop R\limits^{\delta \oplus } \,\mathop {Br}\limits^{\delta \Theta } \, \rightleftharpoons \,\mathop {\boxed{{R^ \oplus }Br^\Theta }}\limits_{(a)} \,\,\, \rightleftharpoons \,\mathop {\boxed{{R^ \oplus }}\,\boxed{Br^\Theta }\,}\limits_{(b)} \,\, \rightleftharpoons $ ${\boxed{{R^ \oplus }}}$ $ + $ $\mathop {\,\boxed{Br^\Theta }\,}\limits_{(c)} \,$