The rate of diffusion of a gas is inversely proportional to

$A$ closed vessel contains an equal number of molecules of $N_2$ and $O_2$ at a pressure of $650 \ mm$. If $N_2$ is completely removed,what will be the pressure in the vessel?

Isochores are drawn at

The rate of diffusion of a gas (molar mass = $128$) compared to oxygen is:

Deep sea divers use a mixture of which gases for respiration?

In which of the following gas mixtures does Dalton's Law of Partial Pressure not apply? Why?
$(i)$ $CO_2 + O_2 + N_2$
$(ii)$ $CO + O_2$
$(iii)$ $NH_3 + HCl$
$(iv)$ $HCl + O_2$