Question

What is `K_"sp"`?

Answer 1

See this old answer.

Explanation:

`K_"sp"` is another equilibrium constant, and measures the solubility of substances in (usually) aqueous solution. If you were working with solutions of precious metals, you would need `K_"sp"` values to ensure that had isolated most of the metal in solution - you don't want to throw gold or platinum or rhodium salts down the drain.

Likewise, if you were working with mercury or cadmium salts, you would not want to throw considerable quantities of these ions down the drain for environmental reasons.