The reaction of methane with concentrated $HNO_3$ at high temperature yields .........

The most important method of preparation of hydrocarbons of lower carbon number is

$Ph-CH=NO_2H$ $\xrightarrow[{3 \ days}]{{isomerises}}$ $\mathop {(x)}\limits_{(50-50\%)}$,Isomer $(x)$ is

$CH_3-CH(CH_3)-CH_2-CH_3 \xrightarrow[hv]{Cl_2} (x)$. Find the number of monochloro products including stereoisomers.

Which is the correct option for the following reaction?
$ 2 CH_3 CH_2 Br \xrightarrow{2 Na / \text{Dry ether}} ? $

Hydrocarbon $(A)$ reacts with bromine by substitution to form an alkyl bromide,which by Wurtz reaction is converted to a gaseous hydrocarbon containing less than four carbon atoms. $(A)$ is