What is the boiling point of $SO_2$ gas (in $K$)?

$A$ certain gas takes three times as long to effuse out as helium. Its molecular mass will be ........... $u$.

At $T \ K$,equal weights of $H_2, D_2$,and $T_2$ are present in a closed vessel. The pressure exerted by this gaseous mixture is $P \ atm$. The ratio of partial pressures of $T_2, D_2$,and $H_2$ is approximately. ($H, D$ and $T$ are isotopes of hydrogen).

$A$ gaseous mixture was prepared by taking equal moles of $CO$ and $N_2$. If the total pressure of the mixture was found to be $1 \ atm$,the partial pressure of the nitrogen $(N_2)$ in the mixture is $...$ $atm$.

If two gases $CH_4$ and $SO_2$ are allowed to enter from the two ends of a $1 \ km$ long vacuum tube at the same time,where will the gases meet from the $CH_4$ end (in $m$)?

The rate of diffusion of two gases $x$ and $y$ is $10 \ mL/sec$ and $40 \ mL/sec$ respectively. The ratio of their molar masses $(Mw)_{x} : (Mw)_{y}$ is: