Phenylmagnesium bromide,upon reaction with a compound $X$ followed by treatment with acid,gives benzyl alcohol. The compound $X$ is

The major aromatic product $C$ in the following reaction sequence will be :

$CH_3CHO$ reacts with aqueous $NaOH$ solution to form

Which of the following does not react with $NaHSO_3$ (sodium bisulphite)?

Given below are the four isomeric compounds $(P, Q, R, S)$. Identify the correct statements from below.
$A$. $Q, R$ and $S$ will give a precipitate with $2,4-DNP$.
$B$. $P$ and $Q$ will give a positive Bayer's test.
$C$. $Q$ and $R$ will give a sooty flame.
$D$. $R$ and $S$ will give a yellow precipitate with $I_2/NaOH$.
$E$. $Q$ alone will deposit silver with Tollen's reagent.
Choose the correct option.

Arrange the following in increasing order of their reactivity for nucleophilic addition reaction: