Q.

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            [2013]

1 1 : 4   
2 1 : 2   
3 6 : 9   
4 8 : 9  

Ans.

(4)

P1M1=P1RT  and  P2M2=P2RT

  P1P2×M1M2=P1P2

43×23=P1P2

  P1P2=89