Identify the reagent $(A)$ used in the following reaction.

Which of the following alkanes cannot be made in good yield by the Wurtz reaction?

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

What is the minimum number of carbon atoms required to exhibit chirality in an alkane?

The maximum number of isomeric monochloro derivatives which can be obtained from $2,2,5,5-$tetramethylhexane by chlorination is $..............$.

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 $(Z)$.