ACS Chemistry Practice Exam 2026 – The All-in-One Guide to Exam Success!

Charles's Law states that at constant pressure, the volume of a given mass of gas is directly proportional to its temperature measured in Kelvin. This means that if you increase the temperature of a gas, the volume will also increase, provided the pressure remains constant.

In practical terms, when a gas is heated, the kinetic energy of its particles increases. Consequently, the particles move more vigorously and tend to spread out more, leading to an increase in volume. This relationship can be expressed mathematically as V ∝ T, where V is the volume and T is the temperature in Kelvin.

The other options do not accurately represent the relationship outlined in Charles's Law. For example, the idea that volume increases while temperature decreases contradicts the fundamental premise of the law. Similarly, the statements involving pressure do not accurately reflect Charles's Law, which specifically deals with the relationship between temperature and volume at constant pressure.