For a process `Delta S_("total") = 0` and `Delta G = 0` was obtained. What does it mean?

For a process DeltaS_(total) = 0 and Delta G = 0 was obtained. What does it mean?

For a process DeltaS_(total ) = 0 and Delta G = 0 was obtained. What does it mean?

Under what condition, E_("cell") = 0 or Delta G = 0 ?

For an irreversible process, DeltaS gt 0 .

A process is non-spontaneous when DeltaS_("total") lt 0 .

How many of the following statement(s) is/are true for free expansion of ideal gas in an insulated container ? 1. It is a Reversible process. 2. Delta H=0 , for this process. 3. Delta E=0 , for this process. 4. Delta(PV)=0 5. Delta T = 0 , for this process. 6. Delta S_("surrounding")=0 , for this process. 7. Delta S_("system")=0 , for this process. 8. Delta S_("total") = 0 , for this process.

Statement-1: For a process to be spontaneous, Delta G as well as Delta S has to be less than zero. Statement-2 : For spontaneous change, Delta S_("total") gt 0

What is the status of a process when (i) Delta G lt 0 (ii) DeltaG = 0 (iii) DeltaG > 0 ? In which of the above cases, the process can be used for obtaining useful work?