In the gas equation PV=RT , V represents the volume of:
A. 1 mol of gas
B. 1g of gas
C. 1 liter of gas
D. Any mass of gas

Hint Given equation is ideal gas equation under standard conditions. Jest recall the conditions. The ideal gas equation (PV=nRT) provides a model of the relations between temperature, volume, pressure and number of particles in a gas. As an ideal model it acts as a reference for the behavior of real gases.

Step by step solution
There exist no such thing like an ideal gas, of course, but many gases behave in some sort as if they were ideal at ordinary working temperatures and pressures.
Assumption for ideal gases are:
1. Gases are made of molecules which move in constant random motion in straight lines.
2. The molecules behave as rigid spheres.
3. There are intermolecular forces between the gas molecules.
4. The volume occupied by the molecules is entirely negligible compared to the volume of the container
5. Three is pressure due to collisions of molecules with the walls of the container.
6. All collisions, both between the molecules themselves, and between the molecules and the walls of the container, are perfectly elastic. (That means that there is no loss of kinetic energy during the collision.)
7. The temperature of the gas is proportional to the average kinetic energy of the molecules.

In : $PV=nRT$
P represents pressure of the ideal gas.
V represents volume of the ideal gas.
n represents the amount of ideal gas measured in terms of moles.
R represents universal gas constant.
T represents temperature.
Thus n=1. Therefore, as represents the number of moles so the answer is A.

Note The ideal gas equation makes some simple assumptions which are not quite true as there is no thing like ideal gas in real. Real gas molecules do have volume and do attract each other. All gases different from ideal behavior under conditions of low temperature (when liquefaction begins) and high pressure (molecules are more, so the volume of the molecule becomes important).