The value of `DeltaH_("transition")` of C (graphite) `rarr` C (diamond) is 1.9 kJ/mol at `25^(@)C`. Entropy of graphite is higher than entropy of diamond. This implies that :

Options

A. C (diamond) is more thermodynamically stable than C (graphite) at `25^(@)C`
B. C (graphite) is more thermodynamically stable than C (diamond) at `25^(@)C`
C. diamond will provide more heat on complete combution at `25^(@)C`
D. `Delta G_("transition")` of C (diamond) `rarr` C(graphite) is -ve

Answer

B, C

Explanation

`C("graphite") rarr C("diamond")`
`Delta H +ve, Delta S = -ve`, So the transition is non spontaneous at all temperatures.