$A$ student has planned to prepare acetanilide from aniline using acetic anhydride. The student has started from $9.3 \ g$ of aniline. However, the student has managed to obtain $11 \ g$ of dry acetanilide. The $\%$ yield of this reaction is $.....$ (in $\%$)

Which set of products will be obtained in the following reactions?
$RCN \xrightarrow{\text{reduction}} (a)$
$RCN \xrightarrow[(ii) H_2O]{(i) CH_3MgBr} (b)$
$RNC \xrightarrow{\text{hydrolysis}} (c)$
$RNH_2 \xrightarrow{HNO_2} (d)$

Product $A$ is

Consider the following reaction sequence:
$p$-Nitrotoluene $\xrightarrow{P} Q$ $\xrightarrow{R} S$ $\xrightarrow{H_2O} T$
$S \xrightarrow{U} \text{Benzoic acid}$
Identify the correct statements from the following:
$(A) P = H_2/Pd, \text{ethanol}; R = NaNO_2/HCl; U = 1. H_3PO_2, 2. KMnO_4-KOH, \text{heat}$
$(B) P = Sn/HCl; R = HNO_2; S = p-\text{toluenediazonium chloride}$
$(C) S = p-\text{toluenediazonium chloride}; T = p-\text{cresol}; U = 1. CH_3CH_2OH, 2. KMnO_4-KOH, \text{heat}$
$(D) Q = p-\text{nitrobenzoic acid}; R = H_2/Pd, \text{ethanol}; T = p-\text{cresol}$
Which of the following combinations is correct?

Amine compounds exhibit ............ isomerism.

The compounds $X$ and $Y$ are respectively: