Question

What will be the pressure exerted by a mixture of $3.2g$ of methane and $4.4g$ of $C{O}_2$ contained in a $9d{m}^3$ flask at $27C$.

Answer 1

The number of moles of methane is $\frac{3.2}{16}=0.2$.
The pressure exerted by methane is $P=\frac{nRT}{V}=\frac{0.2\times 8.314\times 300}{9\times {10}^{-3}}=5.54\times {10}^{4}Pa$.
The number of moles of $C{O}_2$ is $\frac{4.4}{44}=0.1$.
The pressure exerted by $C{O}_2$ is $P^{\prime }=\frac{n^{\prime }RT}{V}=\frac{0.1\times 8.314\times 300}{9\times {10}^{-3}}=2.77\times {10}^{4}Pa$.
The total pressure is $P+P^{\prime }=5.54\times {10}^{4}Pa+2.77\times {10}^{4}Pa=8.31\times {10}^{4}Pa$.