Which is the major product of the following reaction? $CH_3-COCl \xrightarrow{H_2S} \text{product}$

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

Benzamide on reaction with $POCl_3$ gives

The product $(D)$ in the following reaction sequence is: $HOCH_2CH_2CH_2COOCH_2CH_3$ $\xrightarrow{PCC} (A)$ $\xrightarrow[{(1 \ molar \ equivalent)}]{H_2C=CHMgBr} (B)$ $\xrightarrow{NH_4Cl/H_2O} (C)$ $\xrightarrow[H_2O]{KOH}$ $\xrightarrow{H_3O^{+}}$ $\xrightarrow[pyridine]{(CH_3CO)_2O} (D)$

The order of strengths of the following carboxylic acids is:
$(i)$ $CH_3-CH_2-COOH$
$(ii)$ $CH_3-COOH$
$(iii)$ $C_6H_5-COOH$
$(iv)$ $C_6H_5-CH_2-COOH$

For the following three esters, the order of rates of alkaline hydrolysis is:
$(I)$ $p-NO_2-C_6H_4-COOCH_3$
$(II)$ $p-CH_3O-C_6H_4-COOCH_3$
$(III)$ $p-CH_3-C_6H_4-COOCH_3$