The best method for the preparation of $Me_{3}CCN$ is

The reaction of $1$-bromohexane with aqueous $NaOH$ solution follows the order

Consider all the structural isomers with molecular formula $C_5H_{11}Br$. They are separately treated with $KOH$ $(aq)$ to give respective substitution products, without any rearrangement. The number of products which can exhibit optical isomerism from these is . . . . . . .

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 $ ${\boxed{{R^ \oplus }}}$ $ + $ $\mathop {\,\boxed{Br^\Theta }\,}\limits_{(c)} \,$

On heating $CHCl_3$ with aqueous $NaOH$,the product is:

The product $(C)$ in the following reaction sequence is: