Delta S Universe

[Petrina Kan 2I]

Can the equation only apply to reversible reactions? Or can it apply to irreversible reactions as well?

[Bryce Barbee]

I think we only use it with reversible reactions but I am not 100% sure.

[405268063]

In a reversible reaction, delta S of the system is equal to delta S of the surroundings because delta S of the universe is 0. But I'm pretty sure that the general equation you described in your question applies to all reactions.

[Frank He 4G]

That equation can be applied to any situation. It's just telling us that the entropy of the surroundings and the system can be added to get the total change in entropy of the universe. If we're considering an irreversible reaction that happens spontaneously, it will have a positive delta S of the universe.