The molar enthalpies of solution and solubilities of ammonium, sodium and potassium oxalates in water

Abstract

The molar enthalpies of solution of sodium oxalate Δ sol H m (Na 2C 2O 4; T=296.57 K, m=0.00768 mol · kg −1)=(16.59 ± 1.32) kJ · mol −1 and potassium oxalate monohydrate Δ sol H m (K 2C 2O 4 · H 2O; T=299.01 K, m=0.0274 mol · kg −1)=(29.31 ± 0.98) kJ · mol −1 were calorimetrically determined. The case of ammonium oxalate monohydrate, Δ sol H m ((NH 4) 2C 2O 4 · H 2O; T=296.99 K; m=0.03401 mol · kg −1)=(35.0 ± 4.9) kJ · mol −1 was previously considered in [11]. Solubilities of ammonium oxalate, sodium oxalate and potassium oxalate in water were measured in the (273 to 333) K temperature range. Presented data are compared with the literature results.