Schiff's base is prepared from:

In the given set of reactions,identify $D$:
$CH_3COOH$ $\xrightarrow{SOCl_2} A$ $\xrightarrow[Anhy. AlCl_3]{Benzene} B$ $\xrightarrow{HCN} C$ $\xrightarrow{H_2O} D$

Identify $(A)$ in the following reaction sequence:
$\mathop {(A)}\limits_{\text{gives positive iodoform Test}}$ $\xrightarrow[(ii) H^{+}, H_2O, (iii) \text{conc. } H_2SO_4/\Delta ]{(i) CH_3MgBr} (B)$ $\xrightarrow{O_3/Zn, H_2O}$

The reaction of acetophenone with benzaldehyde in the presence of $HCl$ and heat produces product $(A)$. Identify $(A)$.

Correct order for nucleophilic addition reaction :
$(1)$ $C_{6}H_{5}COC_{6}H_{5}$
$(2)$ $C_{6}H_{5}CHO$
$(3)$ $p-CH_{3}C_{6}H_{4}CHO$
$(4)$ $p-CH_{3}OC_{6}H_{4}CHO$

Describe the various chemical reactions of aldehyde and ketone compounds.