1) Two non-reactive monoatomic ideal gases have their atomic masses in the ratio 2:3. The ratio of their partial pressures, when enclosed in a vessel kept at a constant temperature, is 4:3.The ratio of their densities is A) 1:4 B) 1:2 C) 6:9 D) 8:9 Answer: Option DExplanation:$\rho=\frac{P M}{RT}$ $\therefore$ $\rho\propto p M$ or $\frac{\rho_{1}}{\rho_{2}}=\left(\frac{p_{1}}{p_{2}}\right)\left(\frac{M_{1}}{M_{2}}\right)$ $=\left(\frac{2}{3}\right)\left(\frac{4}{3}\right)=\frac{8}{9}$
