$CH_3-CO-OC_2H_5 \xrightarrow{H_2N-NH_2} X$; $CH_3-CO-C_2H_5 \xrightarrow{H_2N-NH_2} Y$. $X$ and $Y$ are:

Treatment of propionaldehyde with dil. $NaOH$ gives:

$A$ compound contains an $\alpha$-hydrogen atom and forms a $\beta$-hydroxy aldehyde in the presence of a dilute alkali. When this product is heated with a dilute acid,it yields unsaturated crotonaldehyde. Identify the compound.

Given below are two statements:
Statement $I:$ The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses because of weak molecular association in aldehydes and ketones due to dipole-dipole interactions.
Statement $II:$ The boiling points of aldehydes and ketones are lower than the alcohols of similar molecular masses due to the absence of $H$-bonding.
In the light of the above statements,choose the most appropriate answer from the options given below:

$CH_3-CO-CH_3$ $\xrightarrow{NaCN/HCl} A$ $\xrightarrow{H_3O^{+}/\Delta} B$. In the above sequence of reactions,$A$ and $B$ are:

Which of the following arrangements with respect to their reactivity in nucleophilic addition reaction is correct?