INTERACTIONS BETWEEN LANTHANIDE CATIONS AND NITRATE ANIONS IN WATER .1. EFFECT OF THE IONIC-STRENGTH ON THE GIBBS ENERGY, ENTHALPY AND ENTROPY OF COMPLEXATION OF THE NEODYMIUM CATION
C. Bonal et al., INTERACTIONS BETWEEN LANTHANIDE CATIONS AND NITRATE ANIONS IN WATER .1. EFFECT OF THE IONIC-STRENGTH ON THE GIBBS ENERGY, ENTHALPY AND ENTROPY OF COMPLEXATION OF THE NEODYMIUM CATION, Journal of the Chemical Society. Faraday transactions, 92(24), 1996, pp. 4957-4963
Citations number
35
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Microcalorimetry has been applied for the first time to the study of t
he very weak complexation of the trivalent neodymium cation by the nit
rate anion in water at 298.15 K. The apparent association constant and
enthalpy of reaction at a given ionic strength are both extracted fro
m the calorimetric data. The ionic strength, which is controlled by ad
dition of sodium perchlorate, is varied from 2.0 to 0.5 mol kg(-1). Fo
r comparison, the association constant is also determined by visible s
pectroscopy under similar conditions. The thermodynamic properties of
complexation are extrapolated to finite dilution using the Fitter inte
raction model: this yields K = 4.0 +/- 0.1 and Delta(r)H(circle minus)
= - 1.2 +/- 0.2 kJ mol(-1). The microcalorimetric method and the data
treatment are fully described.