Which law states that the solubility of a gas in a liquid is proportional to the pressure of the gas above the liquid at constant temperature?

The law that states the solubility of a gas in a liquid is proportional to the pressure of the gas above the liquid at a constant temperature is known as Henry's Law. According to Henry's Law, as the pressure of the gas increases, more gas molecules will dissolve in the liquid. This relationship is crucial in understanding various processes, such as carbonation in beverages, where the pressure of carbon dioxide gas is increased, leading to higher levels of dissolved gas in the liquid.

In contrast, Boyle's Law is related to the behavior of gases under pressure changes while keeping temperature constant; it focuses on the relationship between pressure and volume of a gas, not its solubility in a liquid. Charles's Law describes the relationship between the volume of a gas and temperature at constant pressure, which also does not apply to gas solubility. Dalton's Law pertains to the total pressure of a mixture of gases and how the pressure is the sum of the partial pressures of individual gases, without addressing solubility in liquids. Thus, Henry's Law specifically addresses the effect of gas pressure on solubility, making it the correct principle in this context.