Heat of hydrolysis of phosphorus pentachloride, and heat of formation of aqueous orthophosphoric acid
Abstract
Measurements of the heat of hydrolysis of crystalline phosphorus pentachloride at 25 °C are reported. In conjunction with the available standard heat of formation of PCl5, cryst., (ΔH∘f=–106.0 kcal/mole), the hydrolysis measurements lead to ΔH∘f[H3PO4, (in 100 H2O)]=–309.80 ± 0.35 kcal/mole.