Chloroform reacts with concentrated $HNO_{3}$ to give

The rate of $\beta$-dehydrohalogenation in the following halides under treatment with a strong base follows the order:

$HBr$ reacts with $CH_2=CH-OCH_3$ at room temperature to give

Identify $A$ and $B$ in the following reactions:
$A \xrightarrow[\Delta]{aq. NaOH} C_2H_5OH \xleftarrow{AgOH} B$

The order of reactivity of the following compounds towards the $S_{N}1$ reaction will be:
$(I)$ Benzyl chloride
$(II)$ $p$-Methoxybenzyl chloride
$(III)$ $p$-Nitrobenzyl chloride

Consider the following reaction. Which of the following bases will give the best yield of the alkene $(II)$ as the major product?