Biological Systems MCAT Practice Exam

What is the effect of temperature on gas solubility, according to the principles discussed?

1. Gases become more soluble as temperature increases

2. Gases become less soluble as temperature increases

3. Temperature does not affect gas solubility

4. Increased temperature enhances gas exchange efficiency

The correct answer is: Gases become less soluble as temperature increases

Gases generally become less soluble in liquids as temperature increases. This phenomenon can be explained by the kinetic molecular theory and the principle of gas-liquid equilibrium. As temperature rises, the kinetic energy of gas molecules also increases. This increase in kinetic energy means that gas molecules are more likely to escape from the liquid phase into the gas phase, leading to decreased solubility. Additionally, Henry's Law states that the amount of gas that can dissolve in a liquid is directly proportional to the partial pressure of the gas above the liquid but inversely related to temperature. As temperature increases, the solubility decreases because the increased energy allows gas molecules to overcome the attractive forces from the solvent. In contrast, while increased temperature may enhance certain factors related to gas exchange efficiency in biological systems, this does not change the fundamental relationship between temperature and gas solubility in liquids.