Which of the following catalysts is used in the Rosenmund reaction?

Identify the product '$B$' in the following reaction: $\text{Isopropyl cyanide} \xrightarrow{SnCl_2, HCl} A \xrightarrow{H_3O^+} B + NH_4Cl$

Which sequence of steps describes the best synthesis of $2-$methyl$-3-$pentanone?

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 $\xrightarrow{1. CrO_{2}Cl_{2}, 2. H_{3}O^{+}}$

$CH_3-C(CH_3)(OH)-C(CH_3)(OH)-CH_3 \xrightarrow[H^{+}]{\Delta} ?$

Identify $P$ and $R$ in the given reaction sequence:
$Toluene$ $\xrightarrow[(2) H_3O^+]{(1) CrO_2Cl_2} P$ $\xrightarrow{R} Benzoic \ acid$