The standard molar enthalpies of formation of Cs2MnO4, Cs2Si4O9, and Cs3PO4

✍ Scribed by E.H.P. Cordfunke; W. Ouweltjes

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 148 KB
• Volume: 25
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1993.1097

✦ Synopsis

The molar enthalpies of solution of (\mathrm{Cs}{2} \mathrm{MnO}{4}) in (\left(4.032 \mathrm{~mol} \cdot \mathrm{dm}^{-3} \mathrm{H}{2} \mathrm{SO}{4}+0.106 \mathrm{~mol} \cdot \mathrm{dm}^{-3}\right.) (\left.\mathrm{FeSO}{4}\right), \mathrm{Cs}{2} \mathrm{Si}{4} \mathrm{O}{9}) in (0.09989 \mathrm{~mol} \cdot \mathrm{dm}^{-3} \mathrm{HF}(\mathrm{aq})), and (\mathrm{Cs}{3} \mathrm{PO}{4}) in (3.414 \cdot 10^{-3} \mathrm{~mol} \cdot \mathrm{dm}^{-3}) (\mathrm{H}{3} \mathrm{PO}{4}(\mathrm{aq})) have been measured calorimetrically. From the results the standard molar enthalpies of formation of (\mathrm{Cs}{2} \mathrm{MnO}{4}(\mathrm{~s}), \mathrm{Cs}{2} \mathrm{Si}{4} \mathrm{O}{9}(\mathrm{~s})), and (\mathrm{Cs}{3} \mathrm{PO}_{4}(\mathrm{~s})) have been calculated to give the values (-(1188.3 \pm 3.0) \mathrm{kJ} \cdot \mathrm{mol}^{-1}, \quad-(4297.6 \pm 5.4) \mathrm{kJ} \cdot \mathrm{mol}^{-1}, \quad) and (-(1909.7 \pm 1.7) \mathbf{k J} \cdot \mathbf{m o l}^{-1}), respectively.