Titration Calculator: Unknown Concentration, Volume to Neutralise and pH During the Titration
Work out concentrations and volumes for an acid-base titration, and the pH at any point.
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How this calculator works
Choose the concentration, the volume or the pH case.
Enter the concentrations and volumes you know, and the coefficients from the balanced equation.
The calculator gives the moles of base, the moles of acid and the answer, with the working.
Formulas used
- \frac{C_aV_a}{a} = \frac{C_bV_b}{b}
- \mathrm{pH} = -\log_{10}\frac{n_{H^+} - n_{OH^-}}{V_a + V_b}
Worked example
With the default numbers in the calculator above:
- Moles of base used: 0.0023 mol
- Moles of acid, from the ratio in the balanced equation: 0.0023 mol
- Concentration of the acid: 0.0900 mol/L
Change the numbers in the calculator to see the full working, every step, for your own case.
A second worked example
A different case, with these numbers: What do you want? Volume of base needed to neutralise the acid.
- Moles of acid in the flask: 0.0025 mol
- Moles of base needed: 0.0025 mol
- Volume of base needed (the equivalence point): 25.00 mL
Common questions
How do I calculate the concentration from a titration?
Moles of base = concentration times volume in litres. Use the mole ratio from the equation to get the moles of acid, then divide by the volume of acid.
What is the equivalence point?
The point where the acid and base have reacted in exactly the ratio of the balanced equation. For a strong acid and strong base the pH is 7 there.
What is the difference between the end point and the equivalence point?
The end point is where the indicator changes colour. A good indicator changes very close to the equivalence point.
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Got a question about this? Ask an engineering question and get a plain-language answer with references.
Further reading: Any first-year chemistry text (acid-base titrations).
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