Acetyl bromide reacts with excess of ${\mathrm{CH}}_3\mathrm{MgI}$ followed by treatment with a saturated solution of ${\mathrm{NH}}_4\mathrm{Cl}$ gives

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}\underset{\mathrm{Red} \mathrm{P}}{\overset{{\mathrm{Cl}}_2}{\to }}\left(\mathrm{A}\right)\stackrel{\mathrm{Alcoholic} \mathrm{KOH}}{\to }\left(\mathrm{B}\right)$

What is ($\mathrm{B}$)?

Consider the acidity of the following carboxylic acids:

($1$) $\mathrm{PhCOOH}$

($2$) $\mathrm{o}-{\mathrm{NO}}_2{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{COOH}$

($3$) $\mathrm{p}-{\mathrm{NO}}_2{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{COOH}$

($4$) $\mathrm{m}-{\mathrm{NO}}_2{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{COOH}$

Which of the following orders is correct?

Predict the compound $\mathrm{C}$ in the following series of reactions.

${\mathrm{CH}}_3\mathrm{COOH}\stackrel{{\mathrm{PCl}}_5}{\to }\left[\mathrm{A}\right]\underset{\mathrm{Anhydrous} {\mathrm{AlCl}}_3}{\overset{{\mathrm{C}}_6{\mathrm{H}}_6}{\to }}\left[\mathrm{B}\right]\stackrel{{\mathrm{CH}}_3\mathrm{MgBr}}{\to }\left[\mathrm{C}\right]$

In the given reaction, the product formed is