At the sublimation temperature, for the process `CO_(2)(S)toCO_(2)(g)`

Options

A. `DeltaH , DeltaS` and`DeltaG` are all positive
B. `DeltaH gt 0,DeltaS gt 0` and `DeltaG lt 0`
C. `DeltaH lt 0 , DeltaS gt 0` and `DeltaG lt 0`
D. `DeltaH gt0, DeltaS gt 0` and`DeltaG = 0`

Answer

D

Explanation

As the process is in equilibrium,`DeltaG =0`. But `DeltaG=0`only when the two factors `DeltaH`and `T DeltaS` oppose each other and equal in magnitude `( DeltaG =DeltaH - T DeltaS)`. Thus, we should have either `DeltaH` and `DeltaS`both `+ve` or both -ve, i.e., `DeltaH gt 0` and`DeltaS gt 0` or `DeltaH lt 0` and `DeltaS lt0`