$A$ gas occupies $10 \ L$ at $STP$. Which of the following conditions will result in the same volume?

Calculate the volume in liters for $7 \ g$ of $O_2$ gas at $27 \ ^\circ C$ and $750 \ mm$ of $Hg$ pressure.

If a gas occupies $1 \, L$ volume at atmospheric pressure,what will be the volume of the same amount of gas at $750 \, mm \, Hg$ pressure at the same temperature?

The pressure exerted by a non-reactive gaseous mixture of $6.4 \ g$ of methane and $8.8 \ g$ of carbon dioxide in a $10 \ L$ vessel at $27^{\circ} C$ is .............$kPa$.
(Round off to the Nearest Integer).
[Assume gases are ideal,$R = 8.314 \ J \ mol^{-1} K^{-1}$
Atomic masses $: C = 12.0 \ u, H = 1.0 \ u, O = 16.0 \ u]$

$A$ vacuum vessel of volume $1 \, dm^3$ is evacuated at a constant temperature of $-23 \, ^\circ C$ until the pressure drops to $7.6 \times 10^{-5} \, torr$. What is the number of molecules remaining in the vessel?

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?