Ethyl alcohol exhibits acidic character on reacting with

The reagent used to convert allyl alcohol to acrolein is:

Which of the following compounds is oxidised to prepare methyl ethyl ketone?

What are $X$ and $Y$ in the following reaction sequence?
$C_2H_5OH$ $\xrightarrow{Cl_2} \underline{X}$ $\xrightarrow{Cl_2} \underline{Y}$

$A$ compound with the molecular formula ${C_4}{H_{10}}O$ reacts with sodium and gives a carbonyl compound upon oxidation,which does not reduce Tollen's reagent. What is the original compound?

Product $(B)$ of the given reaction is