Enter the total change in enthalpy (J) and the total number of moles into the calculator to determine the Molar Enthalpy. 

Molar Enthalpy Formula

The following formula is used to calculate the Molar Enthalpy. 

Em = dH / n

  • Where Em is the Molar Enthalpy (J/mol)
  • dH is the total change in enthalpy (J) 
  • n is the total number of moles 

How to Calculate Molar Enthalpy?

The following two example problems outline how to calculate the Molar Enthalpy.

Example Problem #1:

  1. First, determine the total change in enthalpy (J). In this example, the total change in enthalpy (J) is given as 500.
  2. Next, determine the total number of moles. For this problem, the total number of moles is given as 3.
  3. Finally, calculate the Molar Enthalpy using the equation above: 

Em = dH / n

Inserting the values from above and solving the equation: 

Em = 500 / 3 = 166.66 (J/mol)


Example Problem #2: 

Using the same process as above, first define the variables required by the formula. In this case, these values are provided as the following:

total change in enthalpy (J) = 412

total number of moles = 5

Entering these values gives:

Em = 412 / 5 = 82.4 (J/mol)