How does temperature affect the solubility of oxygen in water?
Temperature affects the solubility of oxygen in water in the following way:
According to Henry's Law, the solubility of a gas in a liquid is directly proportional to the partial pressure of that gas. In the case of oxygen in water, as temperature increases, the solubility of oxygen decreases. This means that at higher temperatures, less oxygen can dissolve in water.
To understand this more deeply, you can refer to the table of gas solubility values at different temperatures, known as Henry's Law constants. These constants can provide a quantitative measure of how solubility changes with temperature for different gases.
For example, at 0 degrees Celsius (32 degrees Fahrenheit), the solubility of oxygen in water is approximately 0.0013 moles per liter of water, whereas at 25 degrees Celsius (77 degrees Fahrenheit), the solubility decreases to approximately 0.00056 moles per liter of water.
This decrease in solubility with increasing temperature can be attributed to the kinetic energy of molecules. As temperature rises, the kinetic energy of water molecules also increases, causing them to move more vigorously. This increased molecular motion disrupts the attractive forces between oxygen and water molecules, making it more difficult for oxygen to dissolve.
So, to summarize, an increase in temperature reduces the solubility of oxygen in water by weakening the attractive forces between oxygen and water molecules, resulting in less oxygen gas being able to dissolve in water.