- For solids dissolving to form aqueous solutions
○ Ksp = solubility product constant = 
■ Ksp value depends on ion concentration → more cations & anions = higher value
■ Solids not included in equilibrium expression because their concentration do not change
■ Only affected by temp
- Solubility = s = concentration of solid that dissolves
○ Solubility has the same units as molarity (moles/liters)
○ Solubility can vary with different factors → can speed or slow down the attainment of equilibrium but not its value
■ Ex: Speed up by increasing surface area (grinding up the solid or stirring the solution); decrease as with common ion effect
Solubility Product Practice
- Type 1: Given solubility → calculate Ksp value
1. Write out balanced equation & ICE table
○ S instead of x → solubility is our s that will plug in
- Type 2: Given Ksp → calculate solubility:
2. Write out balanced equation and ICE table
○ Solve for s
Relative Solubilities
- In questions, will be given salts and must be able to decide which one is more soluble/greater molar solubility
- Ksp will only allow us to compare the solubility of salts that fall apart into the same number of ions
○ Bigger Ksp value = more soluble
○ Ex: 
same number of ions so can compare
○ Ex: 
diff number ions so can’t use Ksp to compare
■ Will have to solve for solubility (s) and compare those → bigger s value = more soluble
Calculations Involving Precipitation/Will a Precipitate Form?
- Must calculate Q and compare it to Ksp
○ 
- Focus on the compound whose Ksp value has been given and write balanced equation for how it breaks up
- Steps:
- Set up Q using FINAL Molarity (if not given use M1V1 = M2V2)
■ Do M1V1 = M2V2 for both solutions → plug in the 2 M2 into Q
○ Note: V2 = volume of the 2 solutions combined; M2 = concentration of the ion
- Q > Ksp → Precipitation
- Q < Ksp → No precipitate
- Q = Ksp → Equilibrium