Product $(A)$ of the reaction is

Arrange the following compounds in decreasing order of reactivity towards nucleophilic addition reaction:
$(I)$ $C_6H_5COCH_3$
$(II)$ $CH_3COCH_3$
$(III)$ $CH_3CHO$

The product $(P)$ is formed by the reaction of cyclohexanone with $2$ equivalents of ethanol in the presence of an acid catalyst. The reaction is given as:
Cyclohexanone $+ 2EtOH \xrightarrow{H^+} (P)$
Product $(P)$ is:

Compound $(C)$ is

Which of the following reactions gives a carboxylate ion in their reaction mixture?

Toluene (excess) undergoes the following sequence of reactions:
$(i)$ $CrO_2Cl_2, CS_2$
(ii) $H_3O^+$
(iii) $NaHSO_3$
After filtration,a residue $(A)$ is obtained. This residue $(A)$ reacts with $dil. \ HCl$ to form compound $(B)$.
Identify the structures of residue $(A)$ and compound $(B)$ respectively.