According to Charles's Law, how does temperature affect gas volume?

• A. The volume of a gas is inversely proportional to its absolute temperature.
• B. The volume of a gas remains constant with temperature changes.
• C. The volume of a gas is directly proportional to its absolute temperature.
• D. The volume of a gas increases only at higher pressures.

Answer: (C)

Charles's Law states that the volume of a gas is directly proportional to its absolute temperature when the pressure is held constant. This means that as the temperature of the gas increases, its volume also increases, provided that the pressure does not change. This relationship can be expressed mathematically as V/T = k, where V is the volume, T is the absolute temperature (measured in Kelvin), and k is a constant specific to the amount of gas under consideration.

When the temperature of a gas increases, the kinetic energy of the gas particles also increases, causing them to move more vigorously and spread apart, which results in an increase in volume. Conversely, if the temperature decreases, the kinetic energy decreases, and the gas particles come closer together, leading to a decrease in volume.

This law applies as long as the gas behaves ideally and other variables, such as pressure, are controlled. Understanding this direct proportionality is fundamental in gas law calculations and practical applications in thermodynamics, as it helps to predict how gases will behave under various temperature conditions.