Final answer:
In a reversible process, the change in entropy for the system and surroundings are equal and opposite, keeping the entropy of the universe constant.
Step-by-step explanation:
In a reversible process, the change in entropy of the system (ΔSsys) and the surroundings (ΔSsurr) represent the quantities of heat exchanged, divided by their respective temperatures. When a system goes through a reversible process, the entropy of the universe remains constant; hence, the entropy change of the system is equal in magnitude and opposite in sign to that of the surroundings. For example, if ΔSsys is positive, ΔSsurr will be negative, and their sum (ΔSuniv) will be zero, satisfying the second law of thermodynamics for a reversible process.