All calculatorsNeutralization Calculator
Compute the required volume or molarity of an acid or base to reach equivalence using MₐVₐnₐ = M_bV_bn_b. Supports polyprotic acids (nₐ) and polyhydroxide bases (n_b), unit conversions (mL↔L), clear steps, and visuals (mini chart + equivalence gauge).
Background
At the equivalence point, moles of H⁺ supplied by the acid equal moles of OH⁻ supplied by the base: Mₐ Vₐ nₐ = M_b V_b n_b. Here nₐ is the number of ionizable protons per acid formula unit (e.g., HCl: 1, H₂SO₄: 2), and n_b is the number of hydroxide ions provided per base (e.g., NaOH: 1, Ca(OH)₂: 2).
How to use this calculator
- Enter M (M), V (choose mL/L), and n for both acid and base. Leave exactly one of Mₐ, Vₐ, M_b, V_b blank to solve it.
- We convert mL→L automatically and compute at equivalence using MₐVₐnₐ = M_bV_bn_b.
- Polyprotic/polyhydroxide? Set nₐ or n_b accordingly (e.g., H₂SO₄: nₐ=2; Ca(OH)₂: n_b=2).
Formula & Equation Used
Equivalence: Mₐ Vₐ nₐ = M_b V_b n_b
Solve unknown by isolating it (e.g., V_b = (MₐVₐnₐ)/(M_b n_b)).
Example Problems & Step-by-Step Solutions
Example 1 — HCl vs NaOH (find V_b)
Given: Vₐ=25.00 mL, Mₐ=0.100 M, nₐ=1; M_b=0.200 M, n_b=1.
Convert Vₐ to L: 0.02500 L. Acid equivalents = 0.100×0.02500×1 = 0.00250 eq.
V_b = eq/(M_b n_b) = 0.00250/(0.200×1) = 0.01250 L = 12.50 mL.
Example 2 — H₂SO₄ vs NaOH (find V_b)
Vₐ=25.00 mL → 0.02500 L; Mₐ=0.250 M; nₐ=2 → acid eq = 0.250×0.02500×2 = 0.01250 eq.
With M_b=0.500 M, n_b=1: V_b = 0.01250/(0.500×1) = 0.0250 L = 25.0 mL.
Example 3 — Unknown acid molarity (monoprotic)
Given: Vₐ=25.00 mL → 0.02500 L; V_b=15.00 mL → 0.01500 L; M_b=0.100 M; nₐ=n_b=1.
Mₐ = (M_b V_b n_b)/(Vₐ nₐ) = (0.100×0.01500×1)/(0.02500×1) = 0.0600 M.
Frequently Asked Questions
Q: What do nₐ and n_b mean?
They count H⁺ per acid and OH⁻ per base (e.g., H₂SO₄ has nₐ=2; Ca(OH)₂ has n_b=2).
Q: Does this calculator handle weak acids/bases?
Yes for stoichiometric equivalence (moles H⁺ vs OH⁻). It doesn’t compute pH away from equivalence (buffering/equilibria).
Q: Can I enter volumes in mL?
Yes. We convert mL→L internally.
