Equilibrium Pressures of Oxygen over Mn[sub 2]O[sub 3]-Mn[sub 3]O[sub 4] at Various Temperatures

Abstract

The equilibrium represented by the equation has been studied by measuring the equilibrium pressures of oxygen over . From the data obtained in the 1132°–1247°K range studied ΔH° and ΔS° were calculated for the reaction at and , respectively. These constants can be used in the equation to relate and temperature of the system in the above‐mentioned range with no appreciable additional error. A slight extrapolation showed atm at 1252°K. The above and values were converted to 298.15°K and compared with those in the literature. A new entropy for and a new heat of formation for are indicated from analysis of data in the literature and the present data. This value of entropy of is higher by 1.3 cal/deg (roughly Rln2) than the value taken from the literature.