The rate of effusion of a gas is directly proportional to.....

At a certain temperature, the time required for the complete diffusion of $200 \ mL$ of $H_2$ gas is $30 \ min$. The time required for the complete diffusion of $50 \ mL$ of $O_2$ gas at the same temperature will be: (in $min$)

Under identical conditions,the time required for the diffusion of $64 \ mL$ of $H_2$ gas is equal to the time required for the diffusion of which of the following?

What is the density of water vapour at the boiling point of water?

Diffusion of $CH_{4(g)}$ and $O_{2(g)}$ occurs under similar conditions, then the ratio of their rates of diffusion is

At $T(K)$,a gaseous mixture containing $H_2, He$ and $O_2$ exerted a pressure of $1 \ bar$. The weight percentage of $H_2$ and $He$ is $20$ and $16$ respectively. The partial pressure (in bar) of $H_2, He$ and $O_2$ is respectively