Experimental measurements of heat capacities are often represented in reference works as empirical formulas. For graphite, a formula that works well over a fairly wide range of temperatures is (for one mole)
Cp = a +bT - c/T2
where a= 16.86 J/K, b= 4.77 x 10-3 J/K2, and c= 8.54 x 105 J·K. Suppose, then, that a mole of graphite is heated at constant pressure from 298 K to 500 K. Calculate the increase in its entropy during this process. Add on the tabulated value of 8(298 K) (from the back of this book) to obtain 8(500 K).