What is enthalpy change (ΔH)?

Heat absorbed or released at constant pressure. ΔH = q_p. Positive for endothermic, negative exothermic.

How to calculate from bond energies or calorimetry?

From bonds: sum bonds broken - sum bonds formed. Or q = m c ΔT for calorimeter.

Enthalpy Change Calculator

Calculate ΔH for chemical reactions.

Enthalpy Change Calculator

ΔH°ᵣₓₙ = ΣΔH°ᵟ(products) - ΣΔH°ᵟ(reactants)

Balanced Chemical Equation

Standard Enthalpies of Formation (ΔH°ᵟ)

CH4(g) (kJ/mol)

O2(g) (kJ/mol)

CO2(g) (kJ/mol)

H2O(l) (kJ/mol)

Enthalpy of Reaction

The standard enthalpy of reaction (ΔH°ᵣₓₙ) is the change in enthalpy when a reaction occurs at standard conditions (298.15 K and 1 atm). It's calculated by subtracting the sum of the standard enthalpies of formation of the reactants from that of the products, each multiplied by their stoichiometric coefficients.

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Enthalpy Change Calculator

Standard Enthalpies of Formation (ΔH°ᵟ)

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