In the aeration of wastewater, liquid-gas contact systems are designed to raise the concentration toward equilibrium levels. This goal is accomplished by dispersing air bubbles into the water. An aqueous solution, initially containing 2 × 10-3 kg O2/100 kg H2O is brought into contact with a large volume of ordinary air at 293 K and a total pressure of 1:013 ×105 Pa. At 293 K, the Henry's law constant for the oxygen-water system equals 4:06 × 109 Pa/mol fraction of oxygen in the liquid.
a. Will the solution gain or lose oxygen?
b. What will be the concentration of oxygen in the final equilibrium solution in kg O2 per 100 kg H2O?