Question

The cylinder shown contains 0.79 moles of nitrogen, 0.19 moles of oxygen and 0.02 moles carbon dioxide, a total of 1.00 mole of molecules in the approximate proportion in which they are present in air. Of the three gases, only carbon dioxide is appreciably soluble in the water in the well at the bottom. Assume an equilibrium between dissolved and undissolved carbon dioxide at the beginning and sufficient time lapse to reestablish that equilibrium after the change described. If 0.02 mole of carbon dioxide is forced into the cylinder, the solubility of carbon dioxide ... a) increases by a factor of about 50. b) increases by a factor of about 2. c) increases by 2%. d) remains unchanged. e) decreases.

Answer 1

Answer:

b) increases by a factor of about 2.

Explanation:

Ignore the nitrogen and oxygen. Each gas acts independently of the others.

You have 0.02 mol of CO₂ gas at some pressure in equilibrium with the CO₂ in solution.

According to Graham's Law,

S  = kp

That is, the solubility of a gas in a liquid is directly proportional to its partial pressure above the liquid.

If you add another 0.02 mol of CO₂, you have doubled the number of moles.

According to Avogadro's Law, doubling the number of moles doubles the pressure.

According to Graham's Law, doubling the pressure doubles the solubility.

The solubility of CO₂ increases by a factor of two.