Complete the following reactions:
$1$. Complete oxidation of alkane
$2$. Incomplete combustion of methane

The chemicals and the reaction conditions required for the preparation of ethane are:

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

An alkane (mol. wt. = $86$) on bromination gives only two monobromo derivatives (excluding stereoisomers). The alkane is

Select the chain propagation steps in the free-radical chlorination of methane.
$(1) \, Cl_2 \to 2Cl^{\bullet}$
$(2) \, Cl^{\bullet} + CH_4 \to CH_3Cl + H^{\bullet}$
$(3) \, Cl^{\bullet} + CH_4 \to CH_3^{\bullet} + HCl$
$(4) \, H^{\bullet} + Cl_2 \to HCl + Cl^{\bullet}$
$(5) \, CH_3^{\bullet} + Cl_2 \to CH_3Cl + Cl^{\bullet}$

Natural gas contains mainly