Ostwald's Dilution Law Calculator
⚖ Acids, Bases & Equilibrium. Use the Ostwald's dilution law formula to find ka, degree of dissociation α, concentration: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Ka | no unit |
| Degree of dissociation α | no unit |
| Concentration | mol/L |
Worked example
Find the ka when Degree of dissociation α = 0.0131, Concentration = 0.1 mol/L.
Using Ka = (α² C)/(1 - α): Ka = 1.739 × 10⁻⁵.
Frequently asked questions
What is the formula for Ostwald's dilution law?
Ka = (α² C)/(1 - α).
What do the letters stand for, and what units are used?
Ka, Degree of dissociation α, Concentration in mol/L.
How do you calculate ka?
Put the values into Ka = (α² C)/(1 - α). For example, with Degree of dissociation α = 0.0131, Concentration = 0.1 mol/L, ka = 1.739 × 10⁻⁵.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (ka, degree of dissociation α, concentration) and fill in the others: it rearranges the formula for you.
