Chapter 19, Problem 8RAT

Would you expect to find more dissolved oxygen in polar or tropical ocean waters? Why?

(a) There would be more dissolved oxygen in the tropical oceans because intense tropical storms mix up the atmospheric oxygen into the ocean water.

(b) There would be more dissolved oxygen in the polar oceans because the colder oxygen would "sink" and dissolve into the water.

(c) There would be more dissolved oxygen in the tropical oceans because the heated oxygen molecules in the air would collide with and mix into the water.

(d) There would be more dissolved oxygen in the polar oceans because the solubility of oxygen in water decreases with increasing temperature.

To determine

Whether the dissolved oxygen is found more in polar or tropical oceans.

Answer to Problem 8RAT

The best answer is option (b) as there would be more oxygen in polar oceans as the colder oxygen would sink and dissolve in the water.

Explanation of Solution

Water in natural condition has always some dissolved air but the amount of air may vary at different places. Thus the natural water is considered as a mixture of dissolved gases in water. The amount of air dissolved in water depends upon the solubility of air in water at a particular temperature. Generally, solubility of gases in liquids increases on decreasing the temperature.

As temperature decreases, the solubility of gases in water increases thus the cold water in polar oceans have more dissolved oxygen content than the warm water in tropical oceans.

Conclusion:

Therefore, the best answer is option (b).