All calculatorsNormality (N) Calculator
Determine solution normality and related quantities using equivalents. Supports acid–base, redox, and precipitation contexts via an n-factor (equivalents per mole). Solve for N, grams needed, molarity, volume, or equivalents with student-friendly steps and quick picks.
Background
Normality is defined as equivalents of solute per liter of solution. It is related to molarity by N = M × n, where n is the reaction-specific equivalent factor (e.g., number of ionizable H⁺ for acids, OH⁻ for bases, electrons transferred in redox). Always choose n for the specific reaction you’re working with.
How to use this calculator
- Pick a goal: Solve for N, grams, M, V, or equivalents.
- Set the n-factor: Equivalents per mole, based on your reaction (e.g., H₂SO₄ → 2 for acid–base; KMnO₄ in acid → 5 electrons).
- Enter values: We accept L or mL for volume; conversions are automatic.
- Get steps: We show the formula used, substitutions, and the final value with units.
Tip: For acid–base problems you can usually take n as the number of H⁺ (acid) or OH⁻ (base) delivered per mole. For redox, n equals electrons transferred per mole of reactant (in the balanced reaction).
Formulas & Equations Used
- Normality from molarity: N = M × n
- Normality from mass: N = (m/Mm × n) / V(L)
- Grams for target N: m = N × V(L) × Mm / n
- Molarity from N: M = N / n
- Volume from N, m: V(L) = (m/Mm × n) / N
- Equivalents: Eq = N × V(L)
Example Problems & Step-by-Step Solutions
Example 1 — N from M (acid)
0.250 M H₂SO₄ (n=2) ⇒ N = 0.250 × 2 = 0.500 N.
Example 2 — Grams for target N
Make 250 mL of 0.100 N HCl (Mm = 36.46, n=1). m = 0.100 × 0.250 × 36.46 / 1 = 0.9115 g.
Example 3 — N from mass (redox)
KMnO₄ (Mm = 158.04) in acidic medium (n=5). Dissolve 0.790 g to make 500 mL. N = [(0.790/158.04)×5]/0.500 = 0.0499 N.
Frequently Asked Questions
Q: What is the n-factor?
Equivalents per mole for the specific reaction. For acids: number of ionizable H⁺; bases: OH⁻; redox: electrons transferred per mole.
Q: Is normality always the same for a substance?
No. It depends on the reaction you’re using. Pick n accordingly.
Q: Can I enter mL?
Yes—choose mL and we’ll convert to liters internally.
