For ΔG < 0, a chemical reaction is thermodynamically favourable. That theory and the related theory of reaction kinetics are complex and cannot be
summarised in a few sentences here.
[Edited on 31-7-2015 by blogfast25]diddi - 30-7-2015 at 16:12
how about redox potentials?
for inorganics anyway blogfast25 - 30-7-2015 at 16:16
They only work in watery solutions. As such they are a 'special case' of chemical thermodynamics and kinetics.softbeard - 30-7-2015 at 16:19
In general, a reaction has thermodynamic impetus to go forward if the equation's Gibbs Free Energy change (delta G) is negative (<0). But that's
just thermodynamics. It says nothing about a reaction's kinetics which may be extremely slow and take a very long time before equilibrium is achieved.
Note that the delta G for a reaction may be a strong function of temperature, pressure (in the case of gases/vapours), or both. So it is very
important you consider reaction conditions (eg. 273 Celcius, 1 atm.) while asking this question.