Hess's Law Calculator

Calculate reaction enthalpy changes using Hess's Law principles from thermochemistry

Reactants(e.g., 2H₂ + O₂)

Products(e.g., 2H₂O)

Temperature (K)(Standard: 298.15K)

Pressure (atm)(Standard: 1 atm)

Known Reactions

Reaction 1

Reactants

Products

ΔH (kJ/mol)

Reaction 2

Reactants

Products

ΔH (kJ/mol)

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Quick Tips

1Use consistent units throughout calculations
2Consider significant figures in results
3Document experimental conditions
4Verify results with control calculations