In the following sequence of reactions,the final product $D$ is:

Compound $(A)$ with molecular formula $C_{11}H_8O$ does not undergo self-aldol condensation. Upon ozonolysis,it yields $Ph-CHO$ and $2B$,where $B$ on oxidation with $Ag^{+}$ gives oxalic acid. Identify compound $(A)$.

$A$ compound $A$ with molecular formula $C_{10}H_{13}Cl$ gives a white precipitate on adding silver nitrate solution. $A$ on reacting with alcoholic $KOH$ gives compound $B$ as the main product. $B$ on ozonolysis gives $C$ and $D$. $C$ gives Cannizzaro reaction but not aldol condensation. $D$ gives aldol condensation but not Cannizzaro reaction. $A$ is:

Which of the following is most reactive for a nucleophilic addition reaction?

What is an acetal? Give examples. $OR$ Give the reaction of ethanal with $(a)$ ethanol and $(b)$ ethylene glycol in the presence of dry $HCl$ gas.

Assertion $(A)$: Aldehydes are more reactive than ketones towards nucleophilic addition reactions.
Reason $(R)$: In aldehydes,carbonyl carbon is less electrophilic compared to ketones.
The correct answer is