Which of the following fractions of petroleum refining contains kerosene? (Boiling ranges in $^\circ C$ are given below)

The reagents $A$ and $B$ in the above reaction are:

Methylcyclopentane $\xrightarrow{Br_2/hv} \mathop{Major}\limits_{(X)}$ $\xrightarrow[KOH/\Delta]{Alcoholic} \mathop{Major}\limits_{(Y)}$ $\xrightarrow[Peroxide]{HBr} \mathop{Major}\limits_{(Z)}$
Major final product $(Z)$ is

What is the difference in terms of molar masses of the second and fourth members of a homologous series?

Arrange the following compounds in decreasing order of acidic character of $C-H$ bonds.
$CH_2=CH_2, CH_3-CH_3, C_6H_6, CH\equiv CH$

Product $(C)$ is