If the molar ratio of $CH_4$ and $O_2$ is $1:2$,then the ratio of the rate of diffusion of $O_2$ and $CH_4$ is respectively:

$A$ $10 \ g$ mixture of hydrogen and helium is contained in a vessel of capacity $0.0125 \ m^{3}$ at $6 \ bar$ and $27^{\circ}C$. The mass of helium in the mixture is $g$. (nearest integer) Given : $R = 8.3 \ J \ K^{-1} \ mol^{-1}$ (Atomic masses of $H$ and $He$ are $1 \ u$ and $4 \ u$,respectively)

$80 \ mL$ of $O_2$ takes $2 \ minute$ to pass through a hole. What volume of $SO_2$ will pass through the same hole in $3 \ minute$?

Equal masses of ethyne $(C_2H_2)$ and benzene $(C_6H_6)$ are taken in a flask at $400 \ K$. If the partial pressure of benzene is $600 \ torr$,what will be the total pressure of the gaseous mixture in $torr$?

The rate of diffusion of methane at $1.0 \ atm$ pressure is twice that of another gas '$X$' kept at $1.45 \ atm$. The molecular weight of the gas '$X$' is
[$T$ kept constant]

Explain the fire polishing of glass.