Standard Entropy Change given Gibbs Free Energy Calculator

Change in Entropy Formula:

\[ \Delta S = \frac{\Delta H - G}{T} \]

Change in Entropy (J/kg·K):

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1. What is Standard Entropy Change given Gibbs Free Energy?

Definition: This calculator determines the change in entropy of a thermodynamic system using the Gibbs free energy, enthalpy change, and temperature.

Purpose: It helps in understanding the spontaneity and equilibrium of chemical reactions and physical processes.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \Delta S = \frac{\Delta H - G}{T} \]

Where:

\( \Delta S \) — Change in entropy (J/kg·K)
\( \Delta H \) — Change in enthalpy (J/kg)
\( G \) — Gibbs Free Energy (J)
\( T \) — Temperature (K)

Explanation: The difference between enthalpy change and Gibbs free energy divided by the absolute temperature gives the entropy change.

3. Importance of Entropy Change Calculation

Details: Entropy change helps predict whether a process will occur spontaneously and determines the efficiency of thermodynamic systems.

4. Using the Calculator

Tips: Enter the change in enthalpy (J/kg), Gibbs free energy (J), and temperature in Kelvin. Temperature must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does a negative entropy change mean?
A: A negative value indicates the system becomes more ordered during the process.

Q2: Why must temperature be in Kelvin?
A: The Kelvin scale is an absolute temperature scale required for thermodynamic calculations.

Q3: How is Gibbs free energy related to entropy?
A: Gibbs energy incorporates both enthalpy and entropy to determine process spontaneity at constant pressure and temperature.

Q4: What are typical units for these quantities?
A: Enthalpy change in J/kg, Gibbs energy in J, temperature in K, and entropy change in J/kg·K.

Q5: Can this be used for phase transitions?
A: Yes, this formula applies to any thermodynamic process including phase changes.