$A$ balloon is filled with $500 \,m^3$ of helium gas at $27^{\circ} C$ and $1 \,atm$ pressure. What will be the volume of the helium gas at $-3^{\circ} C$ and $0.5 \,atm$ pressure (in $\,m^3$)?

At the top of a mountain,a thermometer reads $7^{\circ}C$ and a barometer reads $70 \, cm$ of $Hg$. At the bottom of the mountain,these read $27^{\circ}C$ and $76 \, cm$ of $Hg$ respectively. The ratio of the density of air at the top to that at the bottom is

At $NTP$,a sample of equal volume of chlorine and oxygen is taken. What is the ratio of the number of molecules?

The molecular weights of $O_2$ and $N_2$ are $32$ and $28$ respectively. At $15^{\circ}C$,the pressure of $1 \, g$ of $O_2$ will be the same as that of $1 \, g$ of $N_2$ in the same bottle at the temperature of ...... $^{\circ}C$.

The perfect gas equation for $4 \ g$ of hydrogen gas is

The temperature of a gas contained in a closed vessel of constant volume increases by $1^{\circ} C$ when the pressure of the gas is increased by $1 \%$. The initial temperature of the gas is