Advisor(s)
Abstract(s)
The water activities of manganese nitrate solutions were measured using a
humidity sensor instrument up to almost the saturation molality at 298.15 K; the thermodynamic
properties of the system were described by the Pitzer model and specific
interaction theory (SIT). The evaluation of the ion interaction parameters for the Pitzer
model and SIT were carried out using experimental freezing points and osmotic coefficients
of manganese nitrate aqueous solutions, collected from the open literature, and the
water activity data measured in this work. A set of Pitzer and SIT parameters were
estimated using a temperature dependency, that enables us to cover wider temperature
ranges, and consequently calculate system properties to higher molalities. Both approaches
represent very satisfactorily, and with similar accuracy, the experimental data and the
calculated manganese nitrate molal activity coefficients are comparable to those already
published for analogous systems. Additionally, the Pitzer model was also able to calculate
the ice curve and the solubility branch of manganese nitrate hexahydrate up to a salt
solution 6.5 mol-kg-1.
Description
Keywords
Freezing points Osmotic coefficient Pitzer SIT Solubility
Pedagogical Context
Citation
Arrad, Mouad; Aliyeva, Mehriban; Vilas-Boas, Sérgio M.; Kaddami, Mohammed; Sippola, Hannu; Taskinen, Pekka; Pinho, Simão P. (2018). Water activity and freezing points in aqueous solutions of manganese nitrate: experimental and modeling. Journal of Solution Chemistry. ISSN 0095-9782. 47, p. 774-786