Question

What volume of oxygen gas $\left( O _{2}\right)$ measured at $0^{\circ} C$ and $1 \,atm$, is needed to burn completely $1\,L$ of propane gas $\left( C _{3} H _{8}\right)$ measured under the same conditions?

• A. 7 L
• B. 6 L
• C. 5 L
• D. 10 L

Answer 1

Answer: (C)

$\underset{22.4 L}{C_3H_8} + \underset{5 \times 22.4 L}{50 _2} \rightarrow 3CO_2 + 4H_2O$
For the combustion of $22.4 \,L$ propane, oxygen required = $5 \times 22.4 L$
For the combustion of $1 \,L$ of propane oxygen required $\frac {5 \times 22.4}{22.4}L$
$ = 5 \,L$