Q. Identify the correct statement for change of Gibbs energy for a system (ΔG_system) at constant temperature and pressure :
A) If ΔG_system > 0, the process is spontaneous
B) If ΔG_system = 0, the system has attained equilibrium
C) If ΔG_system = 0, the system is still moving in a particular direction
D) If ΔG_system < 0, the process is not spontaneous
Explanation
[Solution from source] At constant temperature and pressure ΔG < 0 means spontaneous, ΔG > 0 means non-spontaneous, and ΔG = 0 means the system is at equilibrium. So ΔG = 0 marks equilibrium, with no net change in any direction. The other statements reverse these signs. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.