What is $Z$ in the following reaction sequence?
$C_6H_5NH_2$ $\xrightarrow[(i) NaNO_2 + HCl / 273 \ K]{(ii) H_3PO_2 + H_2O}$ $\xrightarrow[(iii) CO, HCl, \text{anhydrous } AlCl_3/CuCl]{} Z$

Identify the final product $A$ in the given reaction sequence.

Write the structures of products of the following reactions:
$(i)$ Benzene + $C_{2}H_{5}COCl$ $\xrightarrow{\text{Anhyd. } AlCl_{3}, CS_{2}}$
$(ii)$ $(C_{6}H_{5}CH_{2})_{2}Cd + 2 CH_{3}COCl \rightarrow$
$(iii)$ $H_{3}C - C \equiv C - H$ $\xrightarrow{Hg^{2+}, H_{2}SO_{4}}$
$(iv)$ $p$-Nitrotoluene $\xrightarrow{1. CrO_{2}Cl_{2}, 2. H_{3}O^{+}}$

Identify the reaction shown below:
$C_6H_5CN \xrightarrow[(ii) H_3O^+]{(i) SnCl_2 + HCl} C_6H_5CHO$

What are $X$ and $Y$ in the following reactions?

Identify the reagent used in the following conversion: $\text{Pent-3-enenitrile} \xrightarrow{A} \text{Pent-3-enal}$