Absolute zero $(0\, K)$ is that temperature at which

At the same temperature,pressure,and volume of two gases,which of the following quantities is constant?

$A$ vessel of volume $8 \, L$ contains an ideal gas at $300 \, K$ and $2 \, atm$ pressure. The gas is allowed to leak until the pressure becomes $125 \, kPa$. Calculate the number of moles that leaked out if the temperature remains constant.

If the pressure of a gas increases by $2 \%$ at constant volume,then its temperature

Air is filled at $60^{\circ} C$ in a vessel of open mouth. The vessel is heated to a temperature $t^{\circ} C$ so that $\frac{1}{4}$th of the air escapes from the vessel. Assuming air as an ideal gas and the volume of the vessel remains constant,the value of '$t$' is: (in $^{\circ} C$)

The volume of a gas will be double of what it is at $0^{\circ}C$ (pressure remaining constant) at: