If the Gibbs free energy for a system (ΔGsystem ) is equal to zero, then the system is in equilibrium at constant temperature and pressure. Related Theory Free energy change criteria for predicting spontaneity is better than entropy change criteria because the former requires free energy change of system only whereas the latter requires entropy change of system and surroundings. ΔG>0; the reaction is non-spontaneous and endergonic ΔG<0; the reaction is spontaneous and exergonic ΔG=0; reaction is at equilibrium A Caution According to the second law of thermodynamics entropy of the universe always increases for a spontaneous process. ΔG determines the direction and extent of chemical change.
Identify the correct statement for change of Gibbs energy for a system (Δ G_ system ) at constant temperature and pressure:
NEET UG 2006 — Chemistry Physical Chemistry
2006mcqeasy
Identify the correct statement for change of Gibbs energy for a system (ΔGsystem ) at constant temperature and pressure:
Official previous-year question
Held on 30 Apr 2006 · Verified 9 Jul 2026.
Options
- A
If ΔGsystem <0, the process is not spontaneous
- B
If ΔGsystem >0, the process is spontaneous
- C
If ΔGsystem =0, the system has attained equilibrium
- D
If ΔGsystem =0, the system is still moving in a particular direction
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