Question

Sarah recently learned that O2 is found in the Earth’s water bodies. She was amazed to know the proportion of O2 found in the ocean differs based on the water temperature. What fact did she find out?

A) Sarah found out that cooler parts of the oceans have a higher quantity of dissolved O2, whereas warmer parts of the ocean have a lesser quantity of it.
B) Sarah found out that warmer parts of the oceans have a higher quantity of dissolved O2, whereas cooler parts of the ocean have a lesser quantity of it.
C) Sarah found out that still parts of the oceans have a higher quantity of dissolved O2, whereas tidal parts of the ocean have a lesser quantity of it.

Answer 1

Sarah learned that cooler waters contain higher quantities of dissolved oxygen compared to warmer waters, due to the temperature-dependent solubility of oxygen in water.

Step-by-step explanation:

Sarah found out that the proportion of dissolved O2 (oxygen) in the ocean varies with water temperature, where cooler waters contain a higher quantity of dissolved O2, and warmer waters contain less. The explanation for this phenomenon involves the physical properties of water. Oxygen dissolves in water, but the solubility of oxygen decreases as the temperature rises.

Cooler water, with slower-moving molecules, can hold more oxygen, leading to higher concentrations of dissolved O2. Furthermore, the surface of water bodies, in closer contact with atmospheric oxygen, typically has higher oxygen levels due to absorption from the air, and regions with more sunlight support more photosynthesis, which further increases oxygen levels. However, layers below the surface might have less O2 due to reduced contact with air and sunlight, and the process of decomposers consuming oxygen at deeper layers.