$C_2H_5Cl + KCN$ $\xrightarrow{} X$ $\xrightarrow{\text{Hydrolysis}} Y.$
$X$ and $Y$ are:

The major product $(A)$ of the following reaction is:

An unknown compound $A$ has the molecular formula $C_5H_9Cl$. It does not react with $Br_2 / CCl_4$. When treated with a strong base,it gives a compound $B$ with the molecular formula $C_5H_8$,which reacts with $Br_2 / CCl_4$. Ozonolysis of $B$ followed by treatment with dimethyl sulfide gives a compound with the molecular formula $C_5H_8O_2$. What is the structure of $A$?

In the dehydrohalogenation of $2$-bromobutane,which conformation leads to the formation of $cis$-but-$2$-ene?

Which one of the following is used to obtain the maximum percentage of terminal alkene by dehydrohalogenation of $CH_3CH_2C(CH_3)_2Br$?

The following reaction is a/an:
$CH_3-CH_2-CH_2-Br \xrightarrow{KOH} CH_3-CH=CH_2 + KBr + H_2O$