What are two ways to change solubility limit?

Answer 1

Asked and answered.

Answer 2

Changing the temperature is the easiest way to change solubility limits.

Increasing the temperature will decrease the solubility of gasses in a liquid. It will also increase the solubility of most solids.

Another way to change solubility limits is to take advantage of Le Chatelier's principle or the common ion effect.

As an example, consider solid silver chloride dissolving into ions in water.

AgCl_(s) <---> Ag⁺_(aq) + Cl^-_(aq)

If we dissolve some NaCl into the solution, we will be adding Cl^- to the product side, and the equilibrium will shift to the left, indicating a decrease in solubility. This is an example of the common ion effect.

Alternatively, if we add some NaOH, a second reaction will occur.

Ag⁺_(aq) + OH^-_(aq) ----> AgOH_(s)

The formation of this precipitate will have the effect of removing silver ions from the solution. This amounts to decreasing something on the product side of the first reaction, and will shift it to the right, increasing the solubility of the AgCl.

This secondary reaction was one possible example, and could involve other types of reactions, including acid/base neutralizations and formation of coordination complexes.