Question:
A mixture of hydrogen and oxygen has volume $500 \mathrm{~cm}^{3}$, temperature $300 \mathrm{~K}$, pressure $400 \mathrm{kPa}$ and mass $0.76 \mathrm{~g}$. The ratio of masses of oxygen to hydrogen will be :-
Correct Option: , 3
Solution:
$P V=n R T$
$400 \times 10^{3} \times 500 \times 10^{-6}=n\left(\frac{25}{3}\right)(300)$
$\mathrm{n}=\frac{2}{25}$
$\mathrm{n}=\mathrm{n}_{1}+\mathrm{n}_{2}$
$\frac{2}{25}=\frac{\mathrm{M}_{1}}{2}+\frac{\mathrm{M}_{2}}{32}$
Also $\mathrm{M}_{1}+\mathrm{M}_{2}=0.76 \mathrm{gm}$
$\frac{\mathrm{M}_{2}}{\mathrm{M}_{1}}=\frac{16}{3}$