Arrange the following in decreasing order of their boiling points

(A) 2-methylbutane

(B) 2, 2-dimethyl propane

(C) Pentane

(D) Hexane

An alkyne has the molecular formula $\mathrm{C}_6 \mathrm{H}_{10}$. The number of 1 -alkyne isomers (excluding stereoisomers) possible for it is

Dehydration of an organic acid $X$ with concentrated $\mathrm{H}_2 \mathrm{SO}_4$ at 373 K gives $\mathrm{H}_2 \mathrm{O}$ and gas $Y$. The hybridisation of the carbon in $Y$ and nature of $Y$ are respectively.

Consider the given sequence of reactions,

$$ \mathrm{C}_2 \mathrm{H}_6+\frac{3}{2} \mathrm{O}_2 \xrightarrow[\Delta]{(\mathrm{CH}, \mathrm{COO})_2 \mathrm{Mn}} X \xrightarrow{\mathrm{Na}} Y $$

Electrolysis of aqueous solution of $Y$ gives gases $P$ and $Q$ at anode. $P$ and $Q$ are respectively