pH and Solubility

• The solubility of some salts is affected by the pH of the environment

Basic Solutions

• High pH (more basic) → lots of OH- ions
  • Ex:
    • Increasing pH (adding OH-) → Q >Ksp → decreases solubility of the salt → solubility is less in a basic environment that in pure water

Acidic Solutions

• Low pH (more acidic) environment → lots of hydronium ions (H3O+)
  • Ex:
    • Decreasing pH (adding H+) → Q < Ksp → increased solubility
• General Rule: If the anion X- is an effective base (HX is a weak acid) the salt MX will show increased solubility in an acidic solution
  • Common anions that are effective bases
    • • Salts containing these anions are much more soluble in an acidic solution than in pure water
• Remember: if you have an equilibrium situation where adding more of something that isn’t in eq. Equation then likely that added thing will react with smthn in eq. equation
  • • • Ex:

                               Reaction as a result of adding hydronium → shift in forward direction