Acetone and acetaldehyde can be distinguished by

In a set of the given reactions,acetic acid yielded a product $C$. Product $C$ would be:
$CH_3COOH + PCl_5 \to A$ $\xrightarrow{C_6H_6, \text{anh. } AlCl_3} B$ $\xrightarrow{C_2H_5MgBr, \text{ether}} C$

$x$ is the product obtained from propanenitrile and stannous chloride in the presence of hydrochloric acid followed by hydrolysis. $y$ is the product obtained from but$-2-$ene by ozonolysis followed by hydrolysis. From the following, which product is not obtained when one mole of $x$ and one mole of $y$ react with each other in the presence of alkali followed by heating?

Both ethanal and propanone will react with which of the following?

What product is obtained from the reaction of a Grignard reagent with a ketone?

Among the following,the marked proton of which compound shows the lowest $pK_{a}$ value?