According to Henry's Law, what factors determine the amount of gas that dissolves in water at a given temperature?

The correct answer highlights that gas solubility in water and the partial pressure of the gas in the air are key factors determining the amount of gas that can dissolve in water, as dictated by Henry's Law. This 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 in the air above the liquid.

When the partial pressure of the gas increases, more gas will dissolve in the water until a new equilibrium is reached. This relationship is crucial in various biological and environmental contexts. For example, in the lungs, oxygen dissolves in the blood according to its partial pressure, playing a vital role in respiratory physiology.

Contextually, while the volume of water and atmospheric pressure can influence overall processes in physical chemistry, they do not specifically define gas solubility according to Henry's Law. Temperature and humidity also affect solubility but are not directly tied to Henry's Law in the way that partial pressure is. Gas density and molecular weight may influence how gas behaves but do not directly relate to the dissolution of gas in the water as described by Henry’s Law.