Which gas law explains how gas volume decreases as pressure increases?

The correct choice is based on Boyle's Law, which states that at constant temperature, the volume of a given mass of gas is inversely proportional to the pressure exerted on it. In simpler terms, as the pressure on a gas increases, its volume decreases, provided that the temperature remains unchanged.

This law can be observed in practical scenarios, such as when a diver descends underwater. As the diver goes deeper, the ambient pressure increases due to the weight of the water above them. Consequently, any air-filled spaces, such as lungs or a buoyancy compensator, will decrease in volume as pressure increases. This behavior is critical for divers to understand to prevent barotrauma, which can result from compressed air expanding too rapidly during ascent.

The other gas laws do not describe this specific relationship between pressure and volume. Dalton's Law pertains to the pressures of mixtures of gases, Charles's Law describes how gas volume increases with temperature at constant pressure, and Henry's Law relates to the solubility of gases in liquids under varying pressures. Understanding Boyle's Law is essential for safe and effective dive medicine practices, emphasizing the importance of the relationship between pressure and gas volume in various diving scenarios.