ABSTRACT
To answer this question, one must understand the molar volume of a gas. Molar volume is the amount a substance can occupy given 1 mole of the substance. Solids are the easiest to measure, because they do not change shape. Liquids can be measured by observing how much they can fill when poured into a container. However, the molar volume of a gas is more difficult due to the free-flowing nature of gas molecules. The molar volume of a gas can be determined using the ideal gas law. This equation was first introduced by Emile Clapeyron, and despite the fact that most gases are real and not ideal. It can simply be used for almost every gas given the right conditions. The equation for the ideal gas law equation is
PV = nRT (5.1)
As seen, the molar volume is dependent on the pressure (P), volume (V), and temperature (T). R is also known as the universal gas
constant, which is 0.08206 L atm mol K ⋅ ⋅
, and n is the number of moles of the gas
being used. Through this it is easy to determine a gas’s volume at standard temperature and pressure (STP). Standard temperature and pressure are 0°C (273 K) and 1 atm (760 mmHg). When the equation is solved for the volume of 1 mole of gas at standard temperature and pressure, it is determined that it will occupy 22.4 L. This means that any gas will occupy the same amount of space given the same amount of molecules, the same pressure, and the same temperature.
