Gibbs Free Energy Calculator

Calculate Gibbs free energy, enthalpy, entropy, temperature, and equilibrium constants for chemical reactions. Perfect for thermodynamics, chemical equilibrium, and reaction spontaneity calculations.

Gibbs Free Energy Calculator

About Gibbs Free Energy

Formula

ΔG = ΔH - TΔS

Where R = Gas constant (8.314 J/mol·K)

Key Concepts

  • Gibbs Free Energy (ΔG): Maximum useful work obtainable from a process
  • Enthalpy (ΔH): Heat content change of the system
  • Entropy (ΔS): Measure of disorder or randomness
  • Temperature (T): Absolute temperature in Kelvin

Spontaneity Rules

  • ΔG < 0: Reaction is spontaneous
  • ΔG > 0: Reaction is non-spontaneous
  • ΔG = 0: Reaction is at equilibrium

How to Use

  1. Select the calculation type you want to perform
  2. Enter the required values based on your calculation
  3. Choose appropriate units for your inputs
  4. Click Calculate to get the result

Common Applications

  • Predicting reaction spontaneity
  • Calculating equilibrium constants
  • Phase transition analysis
  • Electrochemical cell potentials
  • Biochemical reaction analysis

Example Values

  • Water freezing: ΔH = -6.02 kJ/mol, ΔS = -22.1 J/mol·K
  • Water boiling: ΔH = 40.7 kJ/mol, ΔS = 109 J/mol·K
  • Standard conditions: T = 298.15 K (25°C)

Important Notes

  • Temperature must be positive (Kelvin scale)
  • Standard temperature is 298.15 K (25°C)
  • Units are automatically converted for calculations
  • Equilibrium calculations use standard temperature
  • All thermodynamic quantities are state functions