Neutralization Calculator
Determine the volume of base needed to neutralize an acid sample or solve for an unknown concentration using equivalent relationships.
Number of acidic protons per mole (e.g., 2 for H₂SO₄).
Number of hydroxide equivalents per mole (e.g., 2 for Ca(OH)₂).
Base volume required
25 mL
Acid equivalents: 0.0025 eq. At equivalence point, base equivalents match acid equivalents.
How to Use This Calculator
Gather titration data
Record acid volume and concentration plus the base concentration. Include valence factors if acids/bases are polyfunctional.
Select the unknown
Choose whether you need the titrant volume to neutralize the acid or the acid concentration from titration results.
Enter the remaining values
Provide the known volumes and concentrations. Units cancel as long as you use consistent molarity units (mol/L).
Read equivalents and answers
The calculator reports equivalents plus either the required titrant volume or the unknown acid concentration.
Formula
Cₐ Vₐ nₐ = C_b V_b n_b
C and V are concentrations and volumes (in mol/L and liters). n denotes valence or number of acidic/basic equivalents per mole.
Example
25.00 mL of 0.100 M HCl (n = 1) requires V_b = (0.100 × 0.0250 × 1) / (0.125 × 1) = 0.020 L = 20.0 mL of 0.125 M NaOH.
Full Description
Acid-base neutralization is governed by the equality of equivalents of acid and base at the equivalence point. Knowing any three of the four variables (acid concentration, acid volume, base concentration, base volume) allows you to solve for the fourth.
This calculator supports titration planning and data analysis by allowing you to solve for titrant volume or analyte concentration while accounting for acids and bases that donate or accept multiple protons.
Frequently Asked Questions
What is valence in this context?
Valence is the number of equivalents per mole. For monoprotic acids/bases it equals 1; for diprotic species it equals 2.
Can I use different volume units?
Yes, as long as all volumes use the same unit. The calculator converts mL to liters internally where required.
Does this account for incomplete neutralization?
No. It assumes complete reaction at equivalence. For weak/weak systems near equilibrium, more detailed equilibrium calculations are needed.
What about indicators?
Indicators signal the endpoint but do not affect the stoichiometry. Ensure the chosen indicator’s color change brackets the equivalence pH.
Can I adapt this for polyprotic titrations?
Yes. Set the valence factor to the number of acidic protons neutralized at the stage of the titration you are analyzing.