How to Calculate and Solve for Entropy of Evaporation | Enthalpy

June 28, 2022 Loveth Idoko

Last Updated on May 23, 2024

The entropy of evaporation is illustrated by the image below. To compute calculate the entropy of evaporation, two essential parameters are needed and these parameters are Enthalpy of Evapourisation (h_fg) and Saturated Temprature (T_s).

The formula for calculating the entropy of evaporation:

S_evap = ^h_fg / _Ts

Where;

S_evap = Entropy of Evapourisation
h_fg = Enthalpy of Evapourisation
T_s = Saturated Temprature

Given an example;
Solve for the entropy of evaporation when the enthalpy of evapourisation is 40 and the saturated temperature is 10.

This implies that;

h_fg = Enthalpy of Evapourisation = 40
T_s = Saturated Temprature = 10

S_evap = ^h_fg / _Ts
That is, S_evap = ⁴⁰ / ₁₀
S_evap = 4

Therefore, the entropy of evapourisation is 4 J/K.

Calculating the Enthalpy of Evapourisation when the Entropy of Evapourisation and Saturated Temperature are Given

h_fg = S_evap x T_s

Where:

h_fg = Enthalpy of Evapourisation
S_evap = Entropy of Evapourisation
T_s = Saturated Temprature

Let’s solve an example;
Find the enthalpy of evapourisation when the entropy of evapourisation is 20 and the saturated temperature is 10.

This implies that;

S_evap = Entropy of Evapourisation = 20
T_s = Saturated Temprature = 10

h_fg = S_evap x T_s
That is, h_fg = 20 x 10
h_fg = 200

Therefore, the enthalpy of evapourisation is 200 J/K.

Calculating the Saturated Temperature when the Entropy of Evapourisation and the Enthalpy of Evapourisation are Given

T_s = ^h_fg / _{S_evap}

Where:

T_s = Saturated Temprature
S_evap = Entropy of Evapourisation
h_fg = Enthalpy of Evapourisation

Let’s solve an example;
Find the saturated temperature when the entropy of evapourisation is 4 and the enthalpy of evapourisation is 40.

This implies that;

S_evap = Entropy of Evapourisation = 4
h_fg = Enthalpy of Evapourisation = 40

T_s = ^h_fg / _{S_evap}
So, T_s = ⁴⁰ / ₄
T_s = 10

Therefore, the saturated temperature is 10 J/K.

How to Calculate Entropy of Evaporation Using Nickzom Calculator

Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the entropy of evapourisation.

To get the answer and workings of the entropy of evapourisation 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 – https://www.nickzom.org/calculator-plus

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 https://www.nickzom.org/calculator

Android (Paid) – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator
Android (Free) – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

Apple (Paid) – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8
Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Materials and Metallurgical under Engineering.

Now, Click on Chemical Reaction Thermodynamics under Materials and Metallurgical

Then, Click on Enthalpy under Chemical Reaction Thermodynamics

Now, Click on Entropy of Evapourisation under Enthalpy

The screenshot below displays the page or activity to enter your values, to get the answer for the entropy of evapourisation according to the respective parameter which is the Enthalpy of Evapourisation (h_fg) and Saturated Temprature (T_s).

Now, enter the values appropriately and accordingly for the parameters as required by the Enthalpy of Evapourisation (h_fg) is 40 and Saturated Temprature (T_s) is 10.

Finally, Click on Calculate

As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the entropy of evapourisation and presents the formula, workings and steps too.