Equilibrium decomposition pressures of the compounds K2ZrCl6 and K2HfCl6

1978 ◽  
Vol 56 (11) ◽  
pp. 1549-1554 ◽  
Author(s):  
G. J. Kipouros ◽  
S. N. Flengas

The chemical equilibria representing the reactions[Formula: see text]and[Formula: see text]were investigated by direct vapour pressure measurements. The thermodynamic data for these reactions, such as free energies and enthalpies of reaction, have been calculated. With reference to the separation of Hf from Zr by a recently developed process based on the selective reactivity of ZrCI4 and HfCl4 vapours with alkali chlorides, it is shown that KCl is a better separating agent than LiCl.

1981 ◽  
Vol 59 (6) ◽  
pp. 990-995 ◽  
Author(s):  
G. J. Kipouros ◽  
S. N. Flengas

The chemical equilibria representing the reactions[Formula: see text]and[Formula: see text]were investigated by direct vapour pressure measurements and thermodynamic data such as free energies and enthalpies of reaction have been calculated.With reference to the separation of Hf from Zr by a recently developed process based on the selective reactivity of ZrCl4 and HfCl4, vapours with alkali chlorides, it is shown that the efficiency of alkali chlorides as separating agents increases in the order of LiCl → NaCl → KCl.


1983 ◽  
Vol 61 (9) ◽  
pp. 2183-2188 ◽  
Author(s):  
G. J. Kipouros ◽  
S. N. Flengas

The chemical equilibria representing the reactions[Formula: see text]and[Formula: see text]were investigated by direct vapour pressure measurements and thermodynamic data such as free energies and enthalpies of reaction have been calculated. The X-ray powder patterns of the compounds Na2HfCl6, K2HfCl6, and Cs2HfCl6 are also reported.With reference to the separation of Hf from Zr by a recently developed process based on the selective reactivity of ZrCl4 and HfCl4 vapours with alkali chlorides, it is shown that the efficiency of alkali chlorides as separating agents increases in the order CsCl → LiCl → NaCl → KCl.


1971 ◽  
Vol 24 (12) ◽  
pp. 2487 ◽  
Author(s):  
CW Childs ◽  
RF Platford

Isopiestic vapour pressure measurements have been made on the systems H2O-NaCl-Na2SO4 and H2O-NaCl-MgSO4 at 15� and 0�. Excess free energies of mixing the aqueous salts hare been calculated for various ionic strengths, and the results have been compared with those previously obtained at 25�. ��� Within experimental uncertainty the excess free energies of mixing of aqueous NaCl with aqueous Na2SO4 are the same at 0�, 15�, and 25�. However, the excess free energy of mixing aqueous NaCl with aqueous MgSO4 shows differences which may be just larger than experimental uncertainty over the same temperature range.


1977 ◽  
Vol 30 (6) ◽  
pp. 1241 ◽  
Author(s):  
PP Singh ◽  
BR Sharma ◽  
KS Sidhu

This paper deals with isothermal total vapour pressure measurements on methanol (B)+pyridine (A), methanol (B)+β-picoline (A), methanol (B)+N,N-dimethylformamide (A) over the whole range of composition at 303.15 K and the excess Gibbs free energies are evaluated. The data have been analysed in terms of a r-mer-r-mer model of interaction. The equilibrium constants for the various association reactions are evaluated and the enthalpy changes ΔH�l involved in the ABx and A2B molecular species of A and B have also been computed.


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