BaF2-LiF

Halides Pbl2i CUCI2, BiOCl, CaF2, BaF2, LiF, NaF... 

The enthalpy of formation of different ternary mixtures were measured by adding one of the three components to the binary mixture formed by the two others. Thus the knowledge of the formation enthalpies of Ndp3-LiF, BaF2-LiF and Bap2-NdF3 binary mixtures was necessary both to calculate from our experimental values the enthalpy of formation of the ternary mixture, but also to calculate this quantity from different models of solution [11-13],... 

The excess molar enthalpies of the BaF2-LiF-NdF3 system were measured in the temperature range 1220-1400 K principally by direct-reaction calorimetry with the direct drop method [16]. A high-temperature calorimeter operable up to 1800 K was used for excess molar enthalpies determinations it has been described several times [17]. 

The enthalpy of formation for some mixtures of this ternary system were obtained by adding solid neodymium fluoride, NdF3, at room temperature, Tg, to the initial BaF2-LiF binary liquid mixture at the... 

This work allowed us, by drop calorimetry at high temperature, to obtain the enthalpies of formation of liquid mixtures for different sections of the ternary system BaF2-LiF-NdF3. Some points of the equilibrium phase diagram were also obtained. 

Rank the following solids in the order of decreasing solubility in liquid HF. Explain the order you give CsF, LiF, BaF2, CaF2, KF. 

The other materials are also a source of impurities - the Ca in the Ca reduction method and the BaF2 and LiF in the electrolytic method. Again, the quality of the final product required determines whether high purity or just ordinary chemically pure materials are needed. 

Name each ionic compound. In each of these compoxmds, the metal forms only one t) e of ion. (a) CsCl (b) SrBr2 (c) K2O (d) LiF 60. Name each ionic compound. In each of these compounds, the metal forms only one type of ion. (a) Lil (b) MgS (c) BaF2 (d) NaF... 

It should be noted however that the enthalpy of mixing curve obtained for the section x(BaF2)/x(LiF) = 9/11 has an inflection point near x(NdF3) = 0.20 which can translate the appearance of a solid phase. Above this concentration, we cannot consider that the mixtures are single-phase liquids. 

Figure 3.5.4 Enthalpy of mixing according to the concentration of NdF, with x(BaF2)/x(LiF) = 9/11...

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