Question

Ordinary air from the atmosphere contains about 21% of oxygen whereas the dissolved air in river water contains about 30%. Give a reason for this.

Answer 1

Dissolved air has a higher percentage of oxygen as compared to ordinary air. Air dissolved in water contains 30 percent oxygen as compared to 21 percent in air. This is because oxygen in the air has a higher solubility than other elements in the air and also there is hydrogen bonding between water and oxygen that increases its solubility.