How to Calculate and Solve for Activation Free Energy | Phase Transformation

Last Updated on December 12, 2022

The image of activation free energy is represented below.

To compute for activation free energy, four essential parameters are needed and these parameters are Surface Free Energy (γ), Latent Heat of Fusion (ΔHf), Melting Temperature of Solid (Kelvin) (Tmand Temperature (Kelvin) (T).

The formula for calculating activation free energy:

ΔG* = 16πγ³Tm²/3ΔHf² (Tm – T)²

&DeltaG* = Activation Free Energy
γ = Surface Free Energy
Tm = Melting Temperature of Solid
T = Temperature
ΔHf = Latent Heat of Fusion

Let’s solve an example;
Find the activation free energy when the surface free energy is 5, the melting temperature of solid is 8, the temperature is 3 and the latent heat of fusion is 10.

This implies that;

γ = Surface Free Energy = 5
Tm = Melting Temperature of Solid = 8
T = Temperature = 3
ΔHf = Latent Heat of Fusion = 10

ΔG* = 16πγ³Tm²/3ΔHf² (Tm – T)²
ΔG* = 16π(5)³(8)²/3(10)²(8 – 3)²
ΔG* = 16π(125)(64)/3(100)(5)²
ΔG* = (402123.8)/3(100)(25)
ΔG* = (402123.8)/(7500)
ΔG* = 53.61

Therefore, the activation free energy is 53.61 J.

Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the activation free energy.

To get the answer and workings of the activation free energy using the Nickzom Calculator – The Calculator Encyclopedia. First, you need to obtain the app.

You can get this app via any of these means:

Web –

To get access to the professional version via web, you need to register and subscribe to have utter access to all functionalities.
You can also try the demo version via

Android (Paid) –
Android (Free) –

Apple (Paid) –
Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Materials and Metallurgical under Engineering.

Now, Click on Phase Transformation under Materials and Metallurgical

Now, Click on Activation Free Energy under Phase Transformation

The screenshot below displays the page or activity to enter your values, to get the answer for the activation free energy according to the respective parameter which is the Surface Free Energy (γ), Latent Heat of Fusion (ΔHf), Melting Temperature of Solid (Kelvin) (Tmand Temperature (Kelvin) (T).

Now, enter the values appropriately and accordingly for the parameters as required by the Surface Free Energy (γ) is 5, Latent Heat of Fusion (ΔHf) is 10, Melting Temperature of Solid (Kelvin) (Tm) is 8 and Temperature (Kelvin) (T) is 3.

Finally, Click on Calculate

As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the activation free energy and presents the formula, workings and steps too.

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