## Abstract

The apparent molal volumes (V_{φ}) 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 V_{φ} have been fitted to the Pitzer equations, V_{φ} = V̄^{0} + (A _{v}I/(1.2m) ln(1 + 1.2I^{0.5}) + 2RTm(β^{V(0)} + β^{V(1)} g(y) + mC^{V}), where V̄^{0} is the infinite dilution partial molal volume, A_{v} is the Debye-Hückel slope, I is the ionic strength, and g(y) = (2/y^{2})·[1-(1 + y) exp(-y)] where y = 2(I^{0.5}). The Pitzer volume parameters β^{V(0)}, β^{V(1)} and C^{V} are functions of temperature. The values of V̄^{0}, β^{V(0)}, β^{V(1)}, and C^{V} 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.

Original language | English (US) |
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Pages (from-to) | 1833-1838 |

Number of pages | 6 |

Journal | Journal of Chemical and Engineering Data |

Volume | 58 |

Issue number | 6 |

DOIs | |

State | Published - Jun 13 2013 |

## ASJC Scopus subject areas

- Chemistry(all)
- Chemical Engineering(all)