Enthalpy of Solution of Sodium Nitrite

An adiabatir solution calorimeter was used to measure enthalpies of solution and dilution of sodium nitrite in water in the concentration range of 5 to 200 mmol · kg^-1. For the solution reaction where molality, m = 100 mmol · kg^-1, ΔC = -1.394 ± 0.014 J · g^-1 · K^-1 (-23.0 ± 0.2 cal · mol^-1 · K^-1). Other ΔC values for some dilution reactions were also measured. The value selected for the enthalpy of solution at infinite dilution is Values for the relative apparent molal heat content ϕ , are tabulated and the enthalpy of transition and of fusion derived from differential thermal analysis measurements are also given.