Question

A gaseous hydrocarbon ($12$ ml) is exploded with an excess of oxygen. On cooling, the contraction in volume is $48$ ml and there is further contraction of $48$ ml in volume when passed through $C{O}_2$. The molecular formula of hydrocarbon is:

• A. $C_3{H}_6$
• B. $C_3{H}_8$
• C. $C_4{H}_{10}$
• D. $C_4{H}_8$

Answer 1

The correct option is D $C_4{H}_8$

Volume of hydrocarbon $=12$ mL

on passing through line water, contraction in volume $=48$ mL

$\therefore$ $n=12$, $nx=48\Rightarrow x=\frac{48}{12}=4$

$\therefore$ Number of carbon in given hydrocarbon $=4$

Only alkenes react with line water,

$\therefore$ Molecular formula $C_n{H}_{2n}=C_4{H}_8$