Home Back

Entropy of Vaporization using Trouton's Rule Calculator

Entropy Formula:

\[ S = (4.5 \times R) + (R \times \ln(T)) \]

K

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is Entropy of Vaporization using Trouton's Rule?

Definition: This calculator estimates the entropy of vaporization using Trouton's rule, which relates the entropy change to the boiling temperature.

Purpose: It helps in thermodynamics calculations to determine the entropy change during phase transition from liquid to vapor.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ S = (4.5 \times R) + (R \times \ln(T)) \]

Where:

Explanation: The formula combines a constant term (4.5R) with a temperature-dependent term (R×ln(T)) to estimate the entropy change.

3. Importance of Entropy Calculation

Details: Entropy of vaporization is crucial for understanding phase transitions, designing heat exchange systems, and predicting thermodynamic behavior.

4. Using the Calculator

Tips: Enter the temperature in Kelvin. The temperature must be greater than 0 K.

5. Frequently Asked Questions (FAQ)

Q1: What is Trouton's Rule?
A: Trouton's rule states that the entropy of vaporization is approximately constant (around 85 J/mol·K) for many liquids at their boiling points.

Q2: Why does the formula include ln(T)?
A: The natural logarithm of temperature accounts for the temperature dependence of the entropy change.

Q3: What units should I use for temperature?
A: Temperature must be in Kelvin (K) for the calculation to be correct.

Q4: What is the typical range of values?
A: For most substances at their boiling points, entropy of vaporization ranges between 80-90 J/mol·K.

Q5: Can I use this for any temperature?
A: This is most accurate near the boiling point. For other temperatures, more complex models may be needed.

Entropy of Vaporization Calculator© - All Rights Reserved 2025