Neutralization Heat Calculator to Find Enthalpy ...

What is Enthalpy of Neutralization?

The enthalpy of neutralization (ΔH_n) is the heat released when an acid and a base react to form 1 mole of water. For all strong acid + strong base reactions, this value is nearly constant at −57.1 kJ/mol because the net ionic reaction is always: H⁺(aq) + OH⁻(aq) → H₂O(l).

🔥 Neutralization Heat Calculator

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📐 Formula

ΔH_n = −57.1 kJ/mol (strong acid + strong base)

Q = m × c × ΔT (calorimetry). ΔH_n = −Q/n_water. Weak acids/bases: less negative due to partial ionization energy cost.

📝 Worked Example

50 mL of 1M HCl + 50 mL of 1M NaOH:
Moles water = 0.05 mol
Calorimeter ΔT = +3.44°C, total mass = 100g
Q = 100 × 4.18 × 3.44 = 1,438 J
ΔH_n = −1438/0.05 = −28,760 J/mol ≈ −57.5 kJ/mol

📝 How to Use the Calculator

Enter Volumes & ConcentrationsInput acid and base volumes (mL) and molarities.

Enter Temperature ChangeΔT from calorimeter reading in °C.

Set Solution Density & SHCUsually 1 g/mL and 4.18 J/g·°C for dilute aqueous solutions.

Calculate ΔHView enthalpy per mole of water formed in kJ/mol.

❓ FAQ

Why do weak acid-base reactions release less heat?

Weak acids/bases are partially ionized, so energy must first be invested to fully ionize them before neutralization proceeds, reducing net heat released.

Is neutralization always exothermic?

Yes — acid-base neutralization is always exothermic. The strong acid + strong base case releases the maximum amount (~57 kJ/mol).

What is Enthalpy of Neutralization?