@nishant sir
how is the delta H = 0
THE DENSITY OF GRAPHITE IS 1.5 AND DENSITY OF DIAMOND IS 3.5 CHANGE IN GIBBS ENERGY IS 1895 JOULE/MOLE.
WHAT IS THE PRESSURE WHEN GRAPHITE CHANGES TO DIAMOND
ΔS=nRln(Vfinal/Vinitial)
ΔG=-TΔStotal
From these,
ΔG=-nRTln(Vfinal/Vinitial)
ΔG=-PVln(7/3)
we know V from density... since n=1 moles...
I am not 100% sure but this must work!