Vapor Pressure Measurements of NaHCOO + H 2 O and KHCOO + H 2 O from 278 to 308 K and Representation with an Ion Interaction (Pitzer) Model

The vapor pressures of NaHCOO(aq) and KHCOO(aq) were measured with a static method. For NaHCOO(aq), measurements were made from (278.15 to 308.15) K and from (0.54 to 12.9) mol·kg −1 . For KHCOO(aq), the measurements cover a temperature range from (278.15 to 323.15) K and extend from (1.03 to 38.8) mol·kg −1 . Published thermodynamic data for the two systems were reviewed, critically assessed, and used together with the present results to evaluate the parameters of a Pitzer-type ion interaction model. Published solubilities of NaHCOO·3H 2 O, NaHCOO·2H 2 O, NaHCOO, and KHCOO were used to evaluate the thermodynamic solubility products. The ion interaction model together with the solubility products allow for the calculation of solubilities and freezing temperatures in the systems (NaHCOO + H 2 O) and (KHCOO + H 2 O) from about (250 to 340) K.