What factors determine the amount of oxygen that will dissolve in water?

The amount of oxygen that will dissolve in water is primarily influenced by temperature and pressure. As water temperature increases, the solubility of gases, including oxygen, generally decreases because warmer water holds less gas compared to cooler water. Additionally, pressure plays a significant role in gas solubility; higher pressure increases the amount of gas that can dissolve in a liquid, while lower pressure reduces it.

While surface tension can affect the gas exchange at the water's surface, it is not a primary factor in determining the overall solubility of dissolved oxygen in water. Similarly, salinity impacts the solubility of gases, but it's not included in your selected answer. Humidity relates more to air conditions rather than the solubility of gases in water. Therefore, focusing on the interplay between temperature and pressure provides the most accurate understanding of oxygen solubility in aquatic environments.