Enter the initial temperature, final temperature, specific heat capacity, and mass into the calculator to determine the enthalpy change of the reaction.

Enthalpy Change Calculation Formula

The following formula is used to calculate the enthalpy change of a reaction.

ΔH = m × c × ΔT / 1000

Variables:

  • ΔH is the enthalpy change (kJ)
  • m is the mass of the substance (g)
  • c is the specific heat capacity (J/g°C)
  • ΔT is the change in temperature (°C)

To calculate the enthalpy change, multiply the mass by the specific heat capacity and the change in temperature, then divide by 1000 to convert from joules to kilojoules.

What is Enthalpy Change?

Enthalpy change refers to the amount of heat absorbed or released during a chemical reaction at constant pressure. It is a crucial concept in thermodynamics, as it helps understand energy changes in chemical processes. Enthalpy change can indicate whether a reaction is exothermic (releases heat) or endothermic (absorbs heat).

How to Calculate Enthalpy Change?

The following steps outline how to calculate the enthalpy change using the given formula.


  1. First, determine the mass of the substance involved in the reaction.
  2. Next, measure the initial and final temperatures to find the change in temperature.
  3. Find the specific heat capacity of the substance.
  4. Use the formula: ΔH = m × c × ΔT / 1000.
  5. Calculate the enthalpy change by inserting the values into the formula.
  6. Check your answer with the enthalpy reaction calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Initial Temperature = 25°C

Final Temperature = 75°C

Specific Heat Capacity = 4.18 J/g°C

Mass = 100 g

FAQ

1. What is enthalpy change?

Enthalpy change is the heat absorbed or released during a chemical reaction at constant pressure.

2. How is enthalpy change different from energy change?

Enthalpy change is specific to processes at constant pressure, whereas energy change can occur under various conditions.

3. How often should I use the enthalpy reaction calculator?

It’s helpful to use the enthalpy reaction calculator whenever there’s a need to determine the heat change in a chemical process.

4. Can this calculator be used for different substances?

Yes, you can adjust the specific heat capacity field to match the substance involved in the reaction.

5. Is the calculator accurate?

The calculator provides an estimate of the enthalpy change based on the inputs provided. For exact figures, it’s best to consult detailed thermodynamic data.