Gibbs free energy and spontaneity

[Liam Maxwell 2E]

Is calculating G the only way to officially conclude spontaneity? Because based on the equation calculating merely entropy or enthalpy doesn't appear to be enough.

[Aijun Zhang 1D]

Yeah, basically you need delta G to determine spontaneity.
Or you can use K to indirectly find the spontaneity at equilibrium.

[Kyle Sheu 1C]

A spontaneous process is one that increases the entropy of the universe, which we can calculate by taking the sum deltaS_sys + deltaS_surr.

So deltaG is not the ONLY way to determine thermodynamic favorability, but as it is often difficult to measure the change in entropies of system and surroundings, we make use of the changes in enthalpy and entropy of the system to calculate deltaG as an applicable method of determining spontaneity.

[Caroline LaPlaca]

Yes because entropy and enthalpy both affect the chance of spontaneity.