How to use the reaction enthalpy at another temperature calculator
Estimate a reaction enthalpy at a new temperature using the heat capacity change of the reaction (Kirchhoff law). Enter enthalpy at temperature 1, heat capacity change of reaction, temperature 1, temperature 2 in the fields above; the enthalpy at temperature 2, change in enthalpy are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “Kirchhoff law enthalpy”, “reaction enthalpy at temperature”, “heat of reaction at high temperature”, “calculate reaction enthalpy at another temperature”, “find enthalpy at temperature 2”.
Formula
Variables
- dH1 — Enthalpy at temperature 1 (kJ/mol)
- dCp — Heat capacity change of reaction (J/(mol·K))
- T1 — Temperature 1 (K)
- T2 — Temperature 2 (K)
Worked example
With enthalpy at temperature 1 = -92 kJ/mol, heat capacity change of reaction = -40 J/(mol·K), temperature 1 = 298 K, temperature 2 = 500 K, the calculator gives enthalpy at temperature 2 ≈ -100.08 kJ/mol; change in enthalpy ≈ -8.08 kJ/mol.
Frequently asked questions
What is the reaction enthalpy at another temperature calculator used for?
Estimate a reaction enthalpy at a new temperature using the heat capacity change of the reaction (Kirchhoff law). It helps with questions such as “Kirchhoff law enthalpy”, “reaction enthalpy at temperature”, “heat of reaction at high temperature”.
What is the formula for the reaction enthalpy at another temperature calculation?
Enthalpy at temperature 2 (kJ/mol) = dH1+dCp × (T2-T1) / 1000. Change in enthalpy (kJ/mol) = [Enthalpy at temperature 2]-dH1. Here dH1 is enthalpy at temperature 1 (kJ/mol), dCp is heat capacity change of reaction (J/(mol·K)), T1 is temperature 1 (K), T2 is temperature 2 (K).
What inputs do I need for the reaction enthalpy at another temperature calculator?
You need enthalpy at temperature 1 in kJ/mol, heat capacity change of reaction in J/(mol·K), temperature 1 in K, temperature 2 in K. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the reaction enthalpy at another temperature calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the reaction enthalpy at another temperature result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.