The product $(A)$ is:

Acetaldehyde $(CH_3CHO)$ reacts with:

An aromatic compound $A$ (Molecular formula $C_{8}H_{8}O$) gives a positive $2,4-DNP$ test. It gives a yellow precipitate of compound $B$ on treatment with iodine and sodium hydroxide solution. Compound $A$ does not give Tollen's or Fehling's test. On drastic oxidation with potassium permanganate,it forms a carboxylic acid $C$ (Molecular formula $C_{7}H_{6}O_{2}$),which is also formed along with the yellow compound in the above reaction. Identify $A, B$ and $C$ and write all the reactions involved.

Acetone and acetaldehyde can be distinguished by

Which of the following aldehydes is less reactive towards nucleophilic addition reaction?

Identify the products of the following reaction:
$HCHO + C_6H_5CHO \xrightarrow[ii. \ H_3O^+]{i. \ conc. \ NaOH} ?$