Question

A gas mixture of $3$ litres of propane $\left(C_3{H}_8\right)$ and butane $\left(C_4{H}_{10}\right)$ on complete combustion at ${250}^{0}C$ produced $10$ litres of $C{O}_2$.

Find out the composition of the gas mixture (Propane: Butane).

• A. $2:1$
• B. $1:2$
• C. $1.5:1.5$
• D. $0.5:2.5$

Answer 1

The correct option is A $2:1$

The reactions are as follows:

$C_3{H}_8+5O_2\to 3C{O}_2+4H_{2}O$
a 3a

$C_4{H}_{10}+\frac{13}{2}{O}_2\to 4C{O}_2+5H_{2}O$
(3-a) 4(3-a)

We know $10$ liters of $C{O}_2$ is produced.

Therefore, $3a+4(3-a)=10$

$\therefore$ $a=2$ (Propane) and $3-2=1$ (Butane)

Hence, Propane : Butane $=2:1$.