Solubility Calculator

Q: What is molar solubility?

Moles of salt that dissolve per liter of pure water at equilibrium. Different from Ksp, which is the product of equilibrium ion concentrations.

Q: What Ksp values mean practically?

Ksp > 10^-3: moderately soluble. 10^-6 to 10^-3: sparingly soluble. < 10^-6: essentially insoluble. AgCl: 1.8x10^-10 (very insoluble).

Q: How does temperature affect Ksp?

Most Ksp values increase with temperature (endothermic dissolution). Exceptions: CaSO4 becomes less soluble above ~40 C.

Q: How do I convert molar solubility to g/L?

Multiply s (mol/L) by M (g/mol). AgCl: s = 1.34x10^-5 mol/L x 143.3 g/mol = 1.92x10^-3 g/L = 1.92 mg/L.

Q: What is the difference between solubility and Ksp?

Solubility (s) = moles that dissolve per liter. Ksp = product of ion concentrations at equilibrium. Ksp = s^2 for MX; Ksp = 4s^3 for MX2.

Calculate molar solubility from Ksp. Find how many moles of a sparingly soluble salt dissolve per liter. Covers MX, MX2, M2X, M2X3 salt types.

💧 Equilibrium📐 s from Ksp based on salt type🧪 Chemistry

Ksp value

Salt type (formula type)

Please enter valid values.

Formula & Reference

Variable	Symbol	Formula	Units
Solubility Calculator	See formula	s from Ksp based on salt type	mol/L

Step-by-Step Examples

Example 1

AgCl MX type

Ksp(AgCl)=1.8x10^-10. MX salt.

Ksp = s^2
s = sqrt(1.8x10^-10) = 1.34x10^-5 mol/L

✓ s(AgCl) = 1.34x10^-5 mol/L = 1.93 mg/L

Example 2

CaF2 MX2 type

Ksp(CaF2)=3.9x10^-11. Salt type MX2 (1 Ca^2+ and 2 F^-).

Ksp = [Ca^2+][F^-]^2 = s(2s)^2 = 4s^3
s = (3.9x10^-11/4)^(1/3) = (9.75x10^-12)^(1/3)
s = 2.14x10^-4 mol/L

✓ s(CaF2) = 2.14x10^-4 mol/L

Example 3

Ag2CrO4 M2X type

Ksp(Ag2CrO4)=1.12x10^-12. M2X salt.

Ksp = [Ag+]^2[CrO4^2-] = (2s)^2(s) = 4s^3
s = (1.12x10^-12/4)^(1/3) = 6.54x10^-5 mol/L

✓ s(Ag2CrO4) = 6.54x10^-5 mol/L

Real-World Applications

💧

Water Treatment

Molar solubility determines maximum concentration of ions before precipitation occurs.

💊

Drug Formulation

Poorly soluble drugs may need salt forms with higher Ksp for adequate bioavailability.

🌊

Environmental Chemistry

Heavy metal precipitation in wastewater depends on metal hydroxide and carbonate Ksp values.

🧪

Analytical Chemistry

Gravimetric analysis requires solubility < 0.1 mg to be quantitative.

Common Mistakes to Avoid

⚠️

Match salt type to formula

CaF2 is MX2 (1 Ca^2+, 2 F^-), not MX. Wrong type gives wrong s.

⚠️

Ksp very sensitive to conditions

Ksp changes with temperature and ionic strength. Values in tables are at 25 C, infinite dilution.

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Solubility in grams per liter

Multiply molar solubility (mol/L) by molar mass (g/mol) to get g/L or mg/L.

Frequently Asked Questions

What is molar solubility? ▾

Moles of salt that dissolve per liter of pure water at equilibrium. Different from Ksp, which is the product of equilibrium ion concentrations.

What Ksp values mean practically? ▾

Ksp > 10^-3: moderately soluble. 10^-6 to 10^-3: sparingly soluble. < 10^-6: essentially insoluble. AgCl: 1.8x10^-10 (very insoluble).

How does temperature affect Ksp? ▾

Most Ksp values increase with temperature (endothermic dissolution). Exceptions: CaSO4 becomes less soluble above ~40 C.

How do I convert molar solubility to g/L? ▾

Multiply s (mol/L) by M (g/mol). AgCl: s = 1.34x10^-5 mol/L x 143.3 g/mol = 1.92x10^-3 g/L = 1.92 mg/L.

What is the difference between solubility and Ksp? ▾

Solubility (s) = moles that dissolve per liter. Ksp = product of ion concentrations at equilibrium. Ksp = s^2 for MX; Ksp = 4s^3 for MX2.

Related Chemistry Calculators

Formula Explorer connections

Interpretation: This formula describes how reactants, products, ions or phases distribute when opposing processes reach equilibrium. Assumption: Use equilibrium rather than initial concentrations, correct stoichiometric exponents, and the specified temperature; activities may replace concentrations in nonideal systems.

Solubility Product Calculator →Ksp Solubility Product Calculator →Solubility vs Temperature Calculator →Chemistry Formula Explorer →