RI 7280 Thermodynamic Data For Ferric Sulfate And Indium Sulfate

The Bureau of Mines determined low-and high-temperature thermodynamic properties for anhydrous ferric sulfate and anhydrous indium sulfate. Low-temperature heat capacities were measured between 50° and 298° K, and enthalpy increments above 298° K were determined. The high-temperature measurements of Fe2(S04)3 extended to 900° K and those of In2(S04)3 to about 1,000° K. A minor transition was found for Fe2(S04)3 at 800° K, with a heat of transition of 540 cal/mole. Tabulations were made of the low-temperature heat capacities and the high-temperature enthalpy and entropy increments. The 298° K entropies derived from the low-temperature measurements were 67.6±0.S ca1/deg mole for ferric sulfate and 72.2±O.5 cal/deg mole for indium sulfate. High-temperature enthalpy increments were also given in equation form.