Which of the following is most acidic?

$C_6H_5COCl + C_6H_5COONa \xrightarrow{\Delta} \text{ . . . . . . }$.

Arrange the products $I$,$II$,$III$ from the following reactions in decreasing order of their acid strength.
$A) \text{Propylbenzene} \xrightarrow[\text{ (ii) } H_3O^{+}]{\text{ (i) } KMnO_4 / OH^{-}} I$
$B) CH_3COOH \xrightarrow[\text{ (ii) } H_2O]{\text{ (i) } Br_2 / \text{red } P} II$
$C) \text{Bromobenzene}$ $\xrightarrow[\substack{\text{ (ii) } CO_2 / \text{dry ether} \\ \text{ (iii) } H_3O^{+}}]{\text{ (i) } Mg / \text{dry ether}} III$

Which of the following compounds reacts with methyl magnesium iodide to produce ethyl acetate?

The reaction is fastest when $X$ is
$R-C(=O)-X + Nu^- \rightarrow R-C(=O)-Nu + X^-$

Identify the final products in the following sequence of reactions: $RCOOH + R'OH \xrightarrow{H^+} \text{intermediate} \xrightarrow[\Delta]{Ni, H_2} \text{Products}$