According to Henry's Law, what is the relationship between gas solubility and partial pressure?

• A. Gas solubility is inversely proportional to the partial pressure of the gas
• B. Gas solubility is directly proportional to the partial pressure of the gas
• C. Gas solubility is unaffected by changes in partial pressure
• D. Gas solubility is dependent on temperature rather than pressure

Answer: (B)

Henry's Law states that at a constant temperature, the amount of gas that dissolves in a liquid is directly proportional to the partial pressure of that gas above the liquid. This means that as the partial pressure of the gas increases, more gas molecules collide with the liquid and enter into solution, resulting in higher gas solubility. Conversely, if the partial pressure decreases, gas escapes from the liquid and solubility decreases.

This relationship is crucial in fields such as respiratory physiology, where the solubility of oxygen and carbon dioxide in blood is vital for understanding gas exchange in the lungs and tissues. It also has applications in areas like scuba diving, where changes in pressure affect how nitrogen is absorbed in the body. Thus, the direct proportionality described in the correct answer reflects a fundamental principle governing the behavior of gases in solution.