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Solubility Product (Ksp) Calculator

Ksp from Molar Solubility

For salt AxBy dissolving: Ksp = (xS)^x · (yS)^y

Molar Solubility from Ksp

Will Precipitate Form? (Q vs Ksp)

Compare ion product Q with Ksp to predict precipitation

Formula

Ksp = [cation]^x × [anion]^y | For AxBy: Ksp = (xS)^x(yS)^y | Precipitate if Q > Ksp

Frequently Asked Questions

What is the solubility product (Ksp)?
Ksp is the equilibrium constant for a sparingly soluble salt dissolving in water. For AxBy(s) ⇌ xA(aq) + yB(aq), Ksp = [A]^x[B]^y. Smaller Ksp = less soluble. It only applies to slightly soluble or insoluble salts.
How do I predict if a precipitate will form?
Calculate the ion product Q using actual ion concentrations. If Q > Ksp, the solution is supersaturated and a precipitate forms. If Q < Ksp, no precipitate (unsaturated). If Q = Ksp, saturated solution.
What is the common ion effect on solubility?
Adding a common ion (one already present from the salt) decreases solubility. For example, adding NaCl to a saturated AgCl solution shifts equilibrium left, decreasing AgCl solubility (Le Chatelier's principle).

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