Abstract
Enthalpy increments above 298 k were determined by the Bureau of Mines for magnesium hydroxide (brucite) between 298 and 900 k by the method of drop calorimetry. Enthalpy and entropy increments from this investigation were combined with other data from the literature to calculate absolute entropies, free energy functions, enthalpies of formation, Gibbs energies of formation, and equilibrium constants of formation from 298 to 900 k. By the use of published pressure- volume-temperature data for water, a table of Gibbs energy change was given for the reaction mgo (periclase)+h20=mg(oh)2 (brucite) as a function of temperature and pressure.