Thermodynamic properties of liquid Zn-Ga solutions, analysis of error caused by side reactions
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The t h e r m o d y n a m i c p r o p e r t i e s of Z n - G a solutions in the t e m p e r a t u r e r a n g e of 714 to 877 K and c o n c e n t r a t i o n r a n g e of zinc Xzn = 0.01 to 0.9 m o l a r f r a c t i o n were d e t e r m i n e d by the emf method u s i n g c o n c e n t r a t i o n c e l l s with liquid e l e c t r o l y t e and e l e c t r o d e s . The lower v a l u e s of both AffZn and ASZn were obtained f r o m slopes. Also the lower value of the i n t e g r a l m o l a r enthalpy AH was d e t e r m i n e d by m e a n s of K r u p k o w s k i ' s f o r m u l a s in c o m p a r i s o n with c a l o r i m e t r i c data. The influence of side r e a c t i o n s , e s p e c i a l l y when the c o m p o n e n t s of i n v e s t i g a t e d alloys a r e close to zinc in the e l e c t r o m o t i v e s e r i e s , may lead to c o n s i d e r a b l e e r r o r s in e s t i m a t i o n of p a r t i a l v a l u e s of t h e r m o d y n a m i c functions. In this case, i n s t e a d of e l e c t r o c h e m i c a l methods, v a p o r p r e s s u r e m e a s u r e m e n t s and, for ZXH, c a l o r i m e t r i c data a r e r e c o m m e n d e d . The magnitude of e r r o r in activity was a n a l y z e d by Wagner and W e r n e r ' s method and c o m p a r e d with the s t a t i s t i c a l a n a l y s i s of e r r o r s b a s e d on e x t e n s i v e e x p e r i m e n t a l data.
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the p r e v i o u s p a p e r s on e v a l u a t i n g t h e r m o d y n a m i c p r o p e r t i e s in dilute liquid zinc alloys in the Zn-Sn, Zn-Cd, ~ Z n - B i , Z n - P b , 2 and Z n - I n 3,a s y s t e m s by the m e a s u r e m e n t of e l e c t r o m o t i v e f o r c e s of c o n c e n t r a t i o n c e l l s , it was shown that the c o m p o n e n t s situated close to zinc in the e l e c t r o m o t i v e s e r i e s , such as Cd and In, c a u s e side r e a c t i o n s b e t w e e n the c o m p o n e n t s m e n tioned and the ZnC12 f r o m the e l e c t r o l y t e . These r e a c tions r e s u l t in the d e c r e a s e of the c o n c e n t r a t i o n of the alloy c o m p o n e n t and in lower emf and dE/d T v a l u e s e s p e c i a l l y at higher t e m p e r a t u r e s . In c o n s e q u e n c e , higher v a l u e s of In YZn a r e obtained. In p r e v i o u s 1-4 papers, the v a l u e s of the s e l f - i n t e r a c t i o n p a r a m e t e r EZZn n were c a l c u l a t e d f r o m plots of In ~'Zn vs X z n to XZn = 0.1; only the qualitative e r r o r s in the d e t e r m i nation of these p a r a m e t e r s were c o n s i d e r e d . The a i m of r e s e a r c h on zinc g a l l i u m s o l u t i o n s o v e r the e n t i r e r a n g e of zinc c o n c e n t r a t i o n was to d e t e r m i n e the t h e r m o d y n a m i c functions and s e l f - i n t e r a c t i o n p a r a m e t e r s , as well as to make a q u a n t i t a t i v e e r r o r a n a l y s i s of the obtained t h e r m o d y n a m i c data by m e a n s of the emf method of c o n c e n t r a t i o n Cells. The s e l e c t i o n of the Z n
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