The standard state Gibb's free energies of formation of C (graphite) and C (diamond) at T = 298   K…
The standard state Gibb's free energies of formation of (graphite) and (diamond) at are
The standard state means that the pressure should be 1 bar, and substance should be pure at a given temperature. The conversion of graphite [ (graphite)] to diamond [ (diamond)] reduces its volume by . If (graphite) is converted to (diamond) isothermally at , the pressure at which (graphite) is in equilibrium with (diamond), is [Useful information: ]