Determination of gibbs energy of formation of cuspidine (3CaO · 2SiO2 · CaF2) from the electromotive force method using CaF2 as the solid electrolyte

The standard Gibbs energy change for the following reaction has been directly determined by electromotive force (EMF) measurement using CaF2 as the solid electrolyte in the temperature range from 1313 to 1329 K. \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$\begin{gathered} 3CaO \cdot 2SiO_2 \cdot CaF_2 (s) + CaO(s) = 2(2CaO \cdot SiO_2 )(s) + CaF_2 (s) \hfill \\ \Delta _r G^ \circ /kJ = 15.9 - 0.0192T( \pm 0.2) \hfill \\ \end{gathered} $$ \end{document} From the preceding results, the standard Gibbs energy of formation of cuspidine has been evaluated for the first time as \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$\Delta _f G^ \circ (cuspidine)/kJmol^{ - 1} = - 5198 + 0.825T( \pm 12)$$ \end{document} The chemical potential diagram for the CaO-SiO2-CaF2 system has been developed at 1323 K based on the thermodynamic data obtained in the present study.