Final answer:
The solubility of dissolved oxygen in water decreases with increasing water temperature, which can have adverse effects on aquatic ecosystems and lead to fish kills. Conversely, colder water temperatures can hold more oxygen.
Step-by-step explanation:
The concentration of dissolved oxygen in water changes with varying temperatures. As the temperature of a body of water increases, the solubility of oxygen decreases. This is due to the physical properties of water which affect gas solubility.
When water temperature rises, oxygen molecules move faster and are less likely to stay dissolved. This can lead to a decrease in the levels of dissolved oxygen, which is vital for the survival of aquatic organisms.
Ecosystems can be adversely affected, potentially leading to events such as large-scale fish kills when the dissolved oxygen levels drop severely. Conversely, as temperatures decrease, the solubility of oxygen in water increases, allowing more oxygen to be held in the liquid phase.
Water exposed to the earth's atmospheric pressure, which includes a partial pressure of oxygen, can reach an oxygen saturation point.
This saturation level varies with temperature; for example, based on Henry's law, at 20 °C and oxygen partial pressure of 101.3 kPa, the concentration of dissolved oxygen is 1.38 × 10-3 mol L-1. The concentration will change if the partial pressure of oxygen changes or if the temperature fluctuates.