Entropy Change Calculator Formula
Understand the math behind the entropy change calculator. Each variable explained with a worked example.
Formulas Used
Entropy Change
entropy_change = heat / temperatureVariables
| Variable | Description | Default |
|---|---|---|
heat | Heat Transferred(J) | 1000 |
temperature | Temperature(K) | 300 |
How It Works
Entropy Change
Entropy measures the disorder or unavailability of energy in a system.
Formula
DeltaS = Q / T
for a reversible process at constant temperature. Positive DeltaS means entropy increases (heat absorbed). The second law states that total entropy of an isolated system never decreases.
Worked Example
1000 J of heat absorbed at 300 K.
- 01DeltaS = Q / T
- 02DeltaS = 1000 / 300
- 03DeltaS = 3.333 J/K
Frequently Asked Questions
What is entropy in simple terms?
Entropy quantifies the number of microscopic arrangements a system can have. Higher entropy means more disorder and less available useful energy.
Can entropy decrease?
Locally, yes (a refrigerator decreases the entropy of its contents). But the total entropy of the universe always increases or stays the same.
What is the second law of thermodynamics?
The total entropy of an isolated system can only increase over time. Heat flows spontaneously from hot to cold, never the reverse.
Learn More
Guide
Thermodynamics Basics: A Complete Guide
Learn the fundamentals of thermodynamics including the four laws, heat transfer, entropy, enthalpy, and the Carnot cycle. Practical explanations with real-world examples.
Ready to run the numbers?
Open Entropy Change Calculator