Gibb's Free Energy

Thermodynamics

Topics

• Nernst Equation

$\Delta G^{°}=-RT\ln K$

• Desmos Calculator
• $\Delta G^{{}^{\circ }}$ is the standard Gibb’s free energy of the reaction at $20^{\circ }\mathrm{C}$
• $R$ is the [ideal gas constant]
• $K$ is the equilibrium constant
• $T$ is the temperature

$\Delta G=\Delta G^{{}^{\circ }}+RT\ln Q=RT\ln \frac{Q}{K}$

• $Q$ is the current balance of $\frac{[\text{product}]}{[\text{reactant}]}$
• $Q<K\to \Delta G<0\to$ spontaneous reaction
• $Q>K\to \Delta G>0\to$ non spontaneous reaction

Statistical Mechanics

$G(\tau ,P,N)\equiv U+PV-\tau \sigma$

$\mathrm{d}G=-\sigma \mathrm{d}\tau +V\mathrm{d}P-\mu \mathrm{d}N$

$G=\mu N$