We can calculate the value of the standard state enthalpy change, H^{o},
and the standard state entropy change, S^{o},
for a chemical change from measurements of the equilibrium constant for
the change at several different temperatures.

**Calculating Enthalpy Changes
and Entropy Changes from the Change in K _{eq} with Temperature**

To determine H^{o}
and S^{o},
plot ln K_{eq} vs 1/T. The resulting straight line
will have a slope equal to -H^{o}/R
and an intercept equal to S^{o}/R.

The derivation for this relationship follows:

We have seen that | |

and | |

Thus we can write | |

or |

This last equation is the equation of a straight line with a a slope of
-H^{o}/R
and an intercept equal to S^{o}/R.