Identify the major product of the following reaction.

What type of reaction is the formation of aldol from aldehyde?

Which will give silver mirror test with Tollens reagent?

The structure of the starting compound $P$ used in the reaction given below is:

$H-CDO + H^{18}O^{-} \rightarrow D-C^{18}O^{-} + CH_2D-OH$. The above reaction is known as:

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 $(A)$.