Partial molal heat capacity of aqueous ferrous chloride from measurements of integral heats of dilution

Heats of dilution of concentrated aqueous solutions (4.43 moles-kg^-1) of FeCl₂ were measured at 15, 25, and 35°C. The heat capacities of these concentrated solutions were also measured at the same temperatures. From these data the partial molal heat capacity, C_p2⁰(FeCl₂, aq, 298.15°K)=-2.56±30 J-°K^-1-mole^-1, was calculated. The partial molal heat capacity of Fe²⁺(aq), -2±30 J-°K^-1-mole^-1, was correlated with the “correspondence principle” equations of Criss and Cobble.