Diamond spontaneously converts to graphite according to the balanced equation Even…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
Diamond spontaneously converts to graphite according to the balanced equation
C(diamond)→C(graphite)
Even though the reaction is thermodynamically favored at 298K, diamonds are commonly considered "forever."
(a) Predict the sign of ΔG298∘ for the conversion of diamond to graphite and justify your prediction with reference to thermodynamic stability.
(b) Explain, in terms of activation energy and molecular kinetics, why a macroscopic diamond shows no observable mass loss over human time scales under ordinary laboratory conditions.
(c) Is a piece of diamond that shows no visible change after several years necessarily at chemical equilibrium with graphite? Use the formal definition of equilibrium and the concept of kinetic control to justify your answer.