A certain amount of gas is sealed in a container of which the volume can change. The relationship between the pressure and volume of the gas at 20 °C is investigated. The results of the experiment are given in the table below.

The gas law represented by the results of the experiment, which shows an inverse relationship between pressure and volume at constant temperature, is Boyle's Law.

A hypothesis for the investigation could be:
If the pressure of a gas is increased at a constant temperature, then its volume will decrease proportionally.

To draw a graph of volume versus pressure, you would plot the pressure values (kPa) on the x-axis and the corresponding volume values ($\text{dm}^3$) on the y-axis. The points would form a curve that decreases as pressure increases, representing an inverse relationship.

The calculated volume in Question 5.4 assumes ideal gas behavior, where gas particles have no volume and no intermolecular forces. Real gases, however, do have finite particle volume and experience intermolecular forces. At high pressures (like $600 \text{ kPa}$), the volume occupied by the gas particles themselves becomes significant, and intermolecular forces become more pronounced, causing the real gas to occupy a slightly larger volume than predicted by ideal gas laws.

A gas will deviate from ideal behavior at LOW temperature conditions.

At low temperatures, the kinetic energy of gas particles decreases, making the attractive intermolecular forces between them more significant. These forces cause the particles to be closer together and reduce the effective pressure they exert, leading to deviations from ideal gas behavior.