$A$ $10 \ g$ of a gas at atmospheric pressure is cooled from $273 \ ^oC$ to $0 \ ^oC$ keeping the volume constant,its pressure would become ............. $atm$.

If $500 \ cm^3$ of hydrogen gas is at a pressure of $760 \ mm$ and a temperature of $300 \ K$,what is the number of moles?

At $200 \ K$,an ideal gas $(X)$ present in a $1 \ L$ flask has a concentration of $1 \ mol \ L^{-1}$. At the same temperature,$0.1 \ mol$ of $X$ is added into the vessel. What is the final pressure of the gas in $atm$?
(Given $R = 0.082 \ L \ atm \ mol^{-1} \ K^{-1}$)

At a temperature of $27\,^oC$,a $2.461 \, L$ vessel contains $0.3 \, mol$ of $N_2$,$0.5 \, mol$ of $He$,and $6.2 \, mol$ of $O_2$ gases. What is the partial pressure of $N_2$ in $atm$?

The densities of $2$ gases are in the ratio $1:2$ and their temperatures are in the ratio $2:1$. What is the ratio of their respective pressures?

What is the molar volume of a gas? What is its value taken as?