= Gibbs free energy
{c}
{title2=$G$}
{wiki}
TODO understand more intuitively how that determines if a reaction happens or not.
$$
\Delta G = \Delta H - T \Delta S
$$
At least from the formula we see that:
* the more exothermic, the more likely it is to occur
* if the entropy increases, the higher the temperature, the more likely it is to occur
* otherwise, the lower the temperature the more likely it is to occur
A prototypical example of reaction that is exothermic but does not happen at any temperature is combustion.
\Video[https://www.youtube.com/watch?v=DKiBA35Nqp4]
{title=Lab 7 - Gibbs Free Energy by MJ Billman (2020)}
{description=Shows the shift of equilibrium due to temperature change with a color change in a HCl CoCl reaction. Unfortunately there are no conclusions because its student's homework.}