MCQ Detailed View

The correct answer is Charles’ Law. This law describes the direct relationship between the volume of a gas and its Kelvin temperature, provided that the pressure remains constant. In simple terms, when a gas is heated, its particles gain kinetic energy, move faster, and push outward with greater force. This results in an increase in volume. Conversely, cooling the gas reduces molecular movement and causes the volume to decrease.

Mathematically, Charles’ Law is expressed as:

V ∝ T or V₁ / T₁ = V₂ / T₂

where V is the gas volume and T is the absolute temperature (measured in Kelvin). This relationship highlights that doubling the Kelvin temperature of a gas doubles its volume, assuming the pressure does not change.

A practical example of Charles’ Law can be seen in hot air balloons. As the air inside the balloon is heated, it expands, becomes less dense than the surrounding cooler air, and causes the balloon to rise. Similarly, a football left outside on a cold winter day will appear deflated because the air inside contracts as temperature decreases.

Charles’ Law is an important component of the ideal gas laws and plays a vital role in chemistry, physics, meteorology, and engineering. It helps explain natural phenomena like weather patterns, the functioning of engines, and the behavior of gases in laboratory experiments.

Thus, Charles’ Law clearly establishes the direct link between gas volume and temperature, making it one of the most fundamental principles in physical chemistry.