Hesss Law Calculator

Introduction to Hess's Law

Hess's Law states that the total enthalpy change for a chemical reaction is the same, regardless of the multiple steps or path by which the reaction takes place. This law is crucial in thermodynamics for calculating the enthalpy changes of reactions that are difficult to measure directly.

How to Use the Calculator

1. Enter the enthalpy changes of up to three known reactions in the respective input fields.
2. Enter the enthalpy change of the target reaction you wish to calculate.
3. Click the "Calculate" button to compute the result.
4. The result will be displayed in the "Result" section.

Example

If you have the following reactions:

• Reaction 1: ΔH1 = -100 kJ/mol
• Reaction 2: ΔH2 = 50 kJ/mol
• Reaction 3: ΔH3 = -20 kJ/mol
• Target Reaction: ΔHtarget = 30 kJ/mol

The enthalpy change for the target reaction can be calculated as:

ΔH = ΔH1 + ΔH2 + ΔH3 - ΔHtarget = -100 + 50 - 20 - 30 = -100 kJ/mol