Boyle’s Gas Law

This standard gas density is used to measure the molar mass of a gas. The density of helium, for example, is about 0.18 grams per liter at STP. The mass of a mole of helium is 4 grams, making the molar volume or the volume a mole of Helium about 22.4 liters. As it turns out, most of the gases have a molar volume at STP of about this same amount. For this reason, when using an equation that uses molar volume, 22.4 liters is used, even though this isn’t 100 percent accurate.

The most ideal gas is one with the smallest molecules and the lowest chance of any type of intermolecular forces. This gas is helium because it has an atomic number of 2 and doesn’t have any forces between molecules. It is also a single atom, unlike hydrogen, which is an H2 gas consisting of two molecules together. Larger gas molecules will take up more space, deviating from the ideal gas, and other gaseous molecules will often interact with other gases, leading to a less ideal situation.

BOYLE’S GAS LAW

Boyle’s gas law was defined by Robert Boyle in 1662 and involved the relationship between pressure and volume, assuming the temperature and amount of gas (n) is constant. What the law states is that the Pressure is inversely proportional to Volume. This graphs out according to Figure 17:

Figure 17.