Skip to content

Gibbs Free Energy Calculator

Chemistry
0.0(0)

Calculates the Gibbs Free Energy (ΔG) of a reaction to determine its spontaneity. A negative ΔG indicates a spontaneous reaction, a positive ΔG indicates a non-spontaneous reaction, and a ΔG of zero indicates equilibrium.

More tools:Science & Lab Calculators
How To Use

How to use this calculator

Start with your values, or try a preset.

Step 1

Enter Enthalpy Change (ΔH), Temperature (T), and Entropy Change (ΔS) in the units shown.

Step 2

Read Gibbs Free Energy (ΔG) and Spontaneity in the results panel. Results update as you change the inputs.

Step 3

Choose a preset to load an example, then adjust the values for your situation.

Worked Examples

Example calculations

See the inputs and their calculated results.

Spontaneous Reaction

Enthalpy Change (ΔH): -100 kJ/mol; Temperature (T): 298 K; Entropy Change (ΔS): 0.1 kJ/(mol·K)

Gibbs Free Energy (ΔG): -129.8 kJ/mol; Spontaneity: Spontaneous

Non-spontaneous Reaction

Enthalpy Change (ΔH): 100 kJ/mol; Temperature (T): 298 K; Entropy Change (ΔS): 0.1 kJ/(mol·K)

Gibbs Free Energy (ΔG): 70.2 kJ/mol; Spontaneity: Non-spontaneous

Equilibrium

Enthalpy Change (ΔH): 29.8 kJ/mol; Temperature (T): 298 K; Entropy Change (ΔS): 0.1 kJ/(mol·K)

Gibbs Free Energy (ΔG): 0 kJ/mol; Spontaneity: At Equilibrium

Explore the topic

Explore More Science & Lab Calculators

Find calculators for chemistry, biology, lab dilution, concentration, osmolarity, genetics, physics, and experimental planning.

Explore tools
People Also Calculate

Related Calculators

Continue with another tool on a related topic.

Chemistry

STP Calculator

Calculates the volume or number of moles of a gas at Standard Temperature and Pressure (STP). STP is defined as 0°C (273.15 K) and 1 atm pressure. This calculator uses the ideal gas law to perform these calculations.

1,470 viewsOpen calculator
Chemistry

Melting Point Calculator

Calculates the melting point of a substance based on the provided pressure. This calculator uses a simplified model and is most accurate for substances with well-defined melting points. Note: This calculator provides estimations and should not be used for critical applications.

1,452 viewsOpen calculator
Chemistry

Osmotic Pressure Calculator

Calculates the osmotic pressure of a solution using the van't Hoff equation. Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane.

1,411 viewsOpen calculator
Chemistry

Van't Hoff Factor Calculator

Calculates the Van't Hoff factor (i), which represents the number of particles a solute dissociates into in a solution. This factor is important in colligative properties calculations.

1,374 viewsOpen calculator