Hess’s Law Calculator
Result:
Explanation:
What is Hess’s Law?
Hess’s Law states that the total enthalpy change during a chemical reaction is the same, regardless of whether it occurs in one step or multiple steps. This principle is based on the idea that enthalpy is a state function, meaning its value depends solely on the initial and final states of the system, not on the path taken to achieve that change. Therefore, when calculating the total energy change in a chemical reaction, it remains constant irrespective of how the reaction proceeds.
How to Use the Hess’s Law Calculator
Step 1: Enter the sum of the enthalpy of formation for all products involved in your chemical reaction into the designated input field labeled “Sum of Enthalpy of Formation of Products (ΔHf products, kJ/mol).”
Step 2: Input the sum of the enthalpy of formation for all reactants into the second input field labeled “Sum of Enthalpy of Formation of Reactants (ΔHf reactants, kJ/mol).”
Step 3: Click on the ‘Calculate ΔH’ button to compute the total enthalpy change (ΔH).
Step 4: Review the displayed result, which shows the calculated value of ΔH in kilojoules per mole (kJ/mol).
Step 5: Read through the explanation provided below the result to understand how this value was derived and its implications regarding whether your reaction is endothermic or exothermic.