Energia livre Gibbs
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
ΔG = ΔH - TΔS
About this calculator
The Gibbs Free Energy calculator is a vital tool for assessing the spontaneity of chemical reactions. Gibbs free energy, denoted by ΔG, measures the energy available to do work in a system. It is calculated using the formula ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.
The formula ΔG = ΔH - TΔS summarizes the relationship between thermal energy and system disorder. When ΔG is negative, the reaction is spontaneous, meaning it can occur naturally. Conversely, when ΔG is positive, the reaction is non-spontaneous and requires external energy to occur. Temperature plays a crucial role, as it can influence reaction spontaneity.
Gibbs free energy is fundamental in various fields, including chemistry, biology, and engineering. It helps predict the feasibility of chemical reactions, which is crucial in developing new materials and industrial processes. Additionally, it is used in biochemical studies to understand how reactions occur within living organisms.
When using the Gibbs Free Energy calculator, it is essential to be mindful of measurement units and ensure that ΔH, T, and ΔS values are accurate. Furthermore, consider specific reaction conditions, such as pressure and temperature, to obtain precise and meaningful results.
Frequently asked questions
What does a negative ΔG mean?
A negative ΔG indicates that the reaction is spontaneous, meaning it can occur naturally without external energy input.
How does temperature affect Gibbs free energy?
Temperature influences Gibbs free energy through the TΔS term in the formula ΔG = ΔH - TΔS. Increasing temperature can make a reaction more or less spontaneous, depending on ΔH and ΔS values.
What are the units of measurement for ΔG, ΔH, and ΔS?
Common units of measurement for ΔG and ΔH are joules (J), and for ΔS, are joules per kelvin (J/K).
Can Gibbs free energy be used for biological reactions?
Yes, Gibbs free energy is widely used in biochemistry to assess the spontaneity of chemical reactions within living organisms.
What precautions should I take when using the Gibbs Free Energy calculator?
Ensure consistent units of measurement and accurate values for ΔH, T, and ΔS. Also, consider specific reaction conditions to obtain precise results.