What product is formed when $1-$chlorobutane reacts with alcoholic $KOH$?

Nitrochloroform (Chloropicrin) is prepared by the action of chloroform and:

What will be the reduction products of the following reactions:
$CHCl_3 \xrightarrow[Zn/HCl \text{ (alc.)}]{+2H}$
$CHCl_3 \xrightarrow[Zn/HCl \text{ (aq.)}]{+4H}$
$CHCl_3 \xrightarrow[Zn/H_2O]{+6H}$

The decreasing order of reactivity of the following organic molecules towards $AgNO_3$ solution is:

An organic compound $A$ $(C_4H_9Cl)$ on reaction with $Na$ in diethyl ether gives a hydrocarbon,which on monochlorination gives only one chloro derivative. $A$ is:

Identify $A$ and $B$ in the following reaction:
$C_2H_5Cl \xrightarrow{A} C_2H_5OH \xleftarrow{B} C_2H_5Cl$