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

The alkane which is next to methane in the homologous series can be prepared from which of the following reactions?
$I$. $2 CH_3 Br \xrightarrow[\text{dry ether}]{Na}$
$II$. $CH_3 COOH \xrightarrow[CaO, \Delta]{NaOH}$
$III$. $CH_3 CH=CH_2 \xrightarrow{H_2 / Pt}$
$IV$. $CH_3 CH_2 Br \xrightarrow[H^{+}]{Zn}$
Correct answer is

Which of the following reactions will not give propane?

Different hydrogen atoms in the compound are represented by alphabets:
$CH_3(A)-CH=CH(B)-CH_2(C)-CH_2(D)-CH(E)(CH_3)_2(F)$
Arrange them in decreasing order of reactivity towards free radical substitution.

Which of the following is not formed by the reaction of $Cl_2$ on $CH_4$ in sunlight?

Identify the correct catalyst and reaction conditions for the controlled oxidation of methane to $(i)$ methanol $(X)$, $(ii)$ methanal $(Y)$ and ethane to $(iii)$ ethanoic acid $(Z)$.