BaSO4 Molar Solubility in Water Calculator

Calculator Form

Ksp at reference temperature

Reference temperature, °C

Target temperature, °C

Dissolution enthalpy, kJ/mol

Initial Ba2+, mol/L

Initial SO4 2-, mol/L

Activity coefficient for Ba2+

Activity coefficient for SO4 2-

Solution volume, L

Molar mass of BaSO4, g/mol

Preferred output unit

Significant digits

Apply temperature correction

Example Data Table

Ksp	Initial Ba2+	Initial SO4 2-	Activity Coefficients	Expected Behavior
1.08e-10	0 mol/L	0 mol/L	1 and 1	Pure water solubility equals square root of Ksp.
1.08e-10	0.001 mol/L	0 mol/L	1 and 1	Common barium ion lowers sulfate release.
1.08e-10	0 mol/L	0.001 mol/L	1 and 1	Common sulfate ion lowers barium release.

Formula Used

For barium sulfate dissolution:

BaSO4(s) ⇌ Ba2+(aq) + SO4 2-(aq)

The thermodynamic solubility product is:

Ksp = γBa[Ba2+] × γSO4[SO4 2-]

With initial ions, the concentration equation is:

(Ba0 + s)(SO40 + s) = Ksp / (γBa × γSO4)

This becomes:

s² + (Ba0 + SO40)s + (Ba0 × SO40 - adjusted Ksp) = 0

For pure water and ideal activity coefficients:

s = √Ksp

Optional temperature correction uses:

ln(K2 / K1) = (-ΔH / R) × (1 / T2 - 1 / T1)

How to Use This Calculator

Enter the Ksp value for BaSO4.
Use zero initial ions for pure water.
Add initial Ba2+ or SO4 2- for common ion cases.
Keep activity coefficients at one for ideal classroom problems.
Enable temperature correction only when enthalpy data is known.
Select your preferred output unit.
Press Calculate to view the result above the form.
Use CSV or PDF export for reports.

About BaSO4 Solubility

Barium sulfate is a sparingly soluble salt. In water it dissolves into barium ions and sulfate ions. The amount is small, yet it is important in chemistry, water testing, scale control, and lab reports. This calculator estimates molar solubility from the solubility product, called Ksp. It also handles common ion effects, activity corrections, and a simple temperature adjustment.

Why This Calculator Helps

Manual solubility work can be slow. You must write an equilibrium expression, build an ICE table, solve a quadratic equation, and convert units. This tool performs those steps in one place. It shows the final molarity, grams per liter, milligrams per liter, dissolved mass for your chosen volume, and the ion product. It also reports whether the starting mixture is unsaturated, saturated, or supersaturated.

Common Ion Effect

If barium ion or sulfate ion is already present, the salt dissolves less. This happens because the equilibrium shifts toward the solid. The calculator uses initial ion concentrations in the quadratic equation. When both starting concentrations are zero, the equation becomes simple. The molar solubility equals the square root of the adjusted Ksp.

Activity And Temperature

Real solutions may not behave ideally. Activity coefficients let you correct the concentration form of Ksp. Lower coefficients usually increase the calculated concentration needed to satisfy the same thermodynamic Ksp. The temperature option uses the van't Hoff relation. It is an estimate, because enthalpy can change with temperature. Use trusted laboratory data when precision is required.

Practical Notes

For classroom problems, leave activity coefficients at one and use 25 degrees Celsius. For water samples, enter measured barium and sulfate concentrations. Compare the ion product with Ksp before adding more solid. If the ion product is greater than Ksp, precipitation is expected. Export the result as CSV or PDF to keep records, attach calculations, or compare several scenarios. Always check units before reporting answers. The example table gives quick reference values for typical inputs. It is not a replacement for formal data tables. It simply shows how Ksp changes final solubility. Use the notes row to explain assumptions. For very concentrated solutions, advanced thermodynamic models may be needed. This calculator is best for dilute mixtures and clear educational reporting for most homework tasks.

FAQs

What is molar solubility?

Molar solubility is the number of moles of solute that dissolve in one liter of solution at equilibrium.

Why does pure BaSO4 use the square root of Ksp?

Pure BaSO4 releases equal amounts of Ba2+ and SO4 2-. Therefore Ksp equals s multiplied by s, so s equals the square root of Ksp.

What is the common ion effect?

The common ion effect lowers solubility when Ba2+ or SO4 2- already exists in solution. The equilibrium shifts toward solid BaSO4.

Can I use this for non-ideal solutions?

Yes. Enter activity coefficients below one when you want a basic non-ideal correction. For exact work, use measured thermodynamic data.

Why does the result become zero?

A zero added solubility result usually means the initial ion product is already above Ksp. The mixture is supersaturated and may precipitate.

What Ksp value should I enter?

Use the Ksp value given in your textbook, lab sheet, or data source. The default is a common classroom value near 25 degrees Celsius.

Is the temperature correction exact?

No. The van't Hoff correction is an estimate. It assumes the dissolution enthalpy remains constant across the temperature range.

Can I save the calculation?

Yes. After calculating, use the CSV button for spreadsheet records or the PDF button for a simple report copy.