Spontaneous Reactions

[Khachik_Hmayakyan_2E]

Is there work being done by or on the system if the reaction is sponanteous?

[Sean_Yue_1E]

A spontaneous chemical reaction is exergonic when it is spontaneous. This means that work is being done by the system on its surroundings, and the ΔG in this case from ΔG = ΔH = TΔS will be negative.

[Laura_funes_1j]

Spontaneous reactions are usually exergonic, meaning that energy flows from the system to the surroundings. The energy released, free energy, can be used to do work.

[LeontyneHenderson2E]

Are there rules for enthalpy and entropy when it comes to whether a reaction is spontaneous or not?

[Stephanie_Younan_3D]

There are rules for enthalpy and entropy, but it depends on the conditions:
If delta H is + and delta S is -, then delta G is nonspontaneous at ALL temperatures
If delta H is - and delta S is -, then delta G is spontaneous at low temperatures
If delta H is + and delta S is +, then delta G is spontaneous at high temperatures
If delta H is - and delta S is +, then delta G is spontaneous at ALL temperatures