The Constitution of Phosphorus Peroxide

✍ Scribed by Prof. Dr. Peter W. Schenk; Dipl. Chem. H. Vietzke

• Publisher: John Wiley and Sons
• Year: 1962
• Tongue: English
• Weight: 130 KB
• Volume: 1
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.196200481

✦ Synopsis

was verified by gas-phase molecular weight determination. The H2S pressure (in mm. Hg) over trithiocarbonic acid between -25 "C. and +15 "C. can be described by the following equation:

The evaluation of the measured values gives AHR = +10.6 f0.3 kcal./mole for the heat of reaction, and ASR = +32.0 f 0.7 e.u./mole for the reaction entropy. The heat of formation and normal entropy of liquid trithiocarbonic acid is then AH$9* = +5.6 & 1.4 kcal./mole, and S298 = +53.3 i 1.3 e.u.1 mole.

The assumption [I] that 1 mole of trithiocarbonic acid dissolves exactly 1 mole of sulfur with the formation of the brown oily tetrathiocarbonic acid H2CS4 proved to be incorrect. Rather, a clear temperature dependence of the sulfur absorption was found; it is only coincidental that at 22 "C. 1 mole of S is dissolved (at +25 "C., 1.08 moles and at -10 OC., 0.50 mole of S per mole of H2CS3). The IRand UV-spectra also point to the solution of sulfur in H2CS3. On the basis of vapor pressure measurements, the heat of solution of sulfur in H2CS3 was determined to be AHs = -0.4f 0.5 kcal. /mole.