Direct measurements of the Gibbs free energy of OH using a cw tunable laser

Abstract
This paper describes an absorption measurement for determining the Gibbs free energy of OH generated in a mixture of water and oxygen vapor. These measurements afford a direct verification of the accuracy of thermochemical data of H2O at high temperatures and pressures. Our results indicate that values for the heat capacity of H2O obtained through numerical computations are correct within our experimental uncertainty of 0.15 cal/mole °K.