TY - JOUR
T1 - Apparent molal volumes of aqueous rare earth salts fit to the Pitzer equation
AU - Rodriguez, Carmen
AU - Prugger, Kaitlan
AU - Millero, Frank J.
PY - 2013/6/13
Y1 - 2013/6/13
N2 - The apparent molal volumes (Vφ) of the trivalent rare earth (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) chlorides, nitrates and perchlorates have been calculated from the density measurements at 25 C and (5 to 80) C and 0.02-4 m. The values of Vφ have been fitted to the Pitzer equations, Vφ = V̄0 + (A vI/(1.2m) ln(1 + 1.2I0.5) + 2RTm(βV(0) + βV(1) g(y) + mCV), where V̄0 is the infinite dilution partial molal volume, Av is the Debye-Hückel slope, I is the ionic strength, and g(y) = (2/y2)·[1-(1 + y) exp(-y)] where y = 2(I0.5). The Pitzer volume parameters βV(0), βV(1) and CV are functions of temperature. The values of V̄0, βV(0), βV(1), and CV for most of the rare earth chlorides are similar orders of magnitude. These results should be useful in estimating the effect of pressure on the equilibria of rare earths in natural waters over a wide range of temperature.
AB - The apparent molal volumes (Vφ) of the trivalent rare earth (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) chlorides, nitrates and perchlorates have been calculated from the density measurements at 25 C and (5 to 80) C and 0.02-4 m. The values of Vφ have been fitted to the Pitzer equations, Vφ = V̄0 + (A vI/(1.2m) ln(1 + 1.2I0.5) + 2RTm(βV(0) + βV(1) g(y) + mCV), where V̄0 is the infinite dilution partial molal volume, Av is the Debye-Hückel slope, I is the ionic strength, and g(y) = (2/y2)·[1-(1 + y) exp(-y)] where y = 2(I0.5). The Pitzer volume parameters βV(0), βV(1) and CV are functions of temperature. The values of V̄0, βV(0), βV(1), and CV for most of the rare earth chlorides are similar orders of magnitude. These results should be useful in estimating the effect of pressure on the equilibria of rare earths in natural waters over a wide range of temperature.
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U2 - 10.1021/je4002398
DO - 10.1021/je4002398
M3 - Article
AN - SCOPUS:84879086608
VL - 58
SP - 1833
EP - 1838
JO - Journal of Chemical & Engineering Data
JF - Journal of Chemical & Engineering Data
SN - 0021-9568
IS - 6
ER -