Entropy Changes in Chemical Reactions (Section)Three of the forms of elemental carbon are...

Entropy Changes in Chemical Reactions (Section)

Three of the forms of elemental carbon are graphite, diamond, and buckminsterfullerene. The entropies at 298 K for graphite and diamond are listed in Appendix C. (a) Account for the difference in the S° values of graphite and diamond in light of their structures (Figure, p. 503). (b) What would you expect for the S° value of buckminsterfullerene (Figure, p. 516) relative to the values for graphite and diamond? Explain.

▲ Figure The structures of (a) diamond and (b) graphite.

▲ Figure Buckminsterfullerene, C60. The molecule has a highly symmetric structure in which the 60 carbon atoms sit at the vertices of a truncated icosahedron. The bottom view shows only the bonds between carbon atoms.