Identify the correct statement for change of Gibbs energy for a system `(DeltaG_(system))` at constant temperature and pressure:

Options

A. If `DeltaG_("system") gt 0`, the process is spontaneous
B. If `DeltaG_("system") = 0` the system has attained equilibrium
C. If `DeltaG_("system") = 0`, the system is still moving in a particlular direction
D. If `DeltaG_("system") lt 0`, the process is not spontaneous

Answer

B

Explanation

If the Gibbs free energy for a system `(DeltaG_("system"))` is equal to zero, then system is present in equilibrium at a constant temperature and pressure
`DeltaG=Delta_(I)G^(@)+ RT "In " K, DeltaG=0`
`Delta_(I)G^(@)=-RT "In " K`
K=equilibrium constant
If `DeltaG_("system") lt 0` , then the process is spontaneous