The major product formed in the following reaction is
(Structure of the reactant) $\xrightarrow[{CHCl_3}]{{PCC}}$

In the presence of peroxide,styrene reacts with $HBr$ to give $X$. When $X$ is reacted with magnesium in dry ether followed by $CO_2$ and hydrolysis,it gives $Y$. Treatment of $Y$ with $PCl_5$ and then with $H_2, Pd-BaSO_4$ gives $Z$. What is $Z$?

Aromatic aldehydes undergo disproportionation in the presence of concentrated sodium or potassium hydroxide to give the corresponding alcohol and acid salt. This reaction is known as:

The product $(A)$ is:

Explain the addition of a $Grignard$ reagent to aldehyde and ketone compounds.

Which of the following reactions converts the carbonyl group of aldehydes and ketones to a methylene group on treatment with zinc amalgam and concentrated $HCl$?