AP Chemistry / Unit 7: Equilibrium
7.11 Introduction to Solubility Equilibria
Notes
For a slightly soluble salt: $AgCl(s)\rightleftharpoons Ag^++Cl^-$, $K_{sp}=[Ag^+][Cl^-]$.
- Molar solubility $s$: for $\mathrm{AB}$, $K_{sp}=s^2$; for $\mathrm{AB_2}$, $K_{sp}=4s^3$.
Practice
$K_{sp}$ of AgCl is $1.6\times10^{-10}$. Molar solubility:
$\displaystyle \sqrt{1.6\times10^{-10}}$.
The $K_{sp}$ expression for $\mathrm{PbI_2}$:
Solid omitted; coefficient becomes exponent.
A larger $K_{sp}$ (same formula type) means:
More ions in solution.
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