Delta S total in reversible expansion

[Joanna Jin 1J]

Why is delta S total equal to zero in reversible expansion?

[Seena Amin-Sanayei 2D]

Since in reversile equations we're taking the entropy from the surroundings ∆Ssys = ∆Ssurr and therefore ∆Stot = 0

[Yifan_Wang_2A]

Delta S total in reversible expansion is 0 because the reaction is at equilibrium and the delta S system equals delta S surroundings. The reaction starts and ends in the same place.