The head of a “strike anywhere” match contains tetraphosphorus trisulfide, P4S3. In an experiment, a student burned this compound in an excess of oxygen and found that it evolved 3651 kJ of heat per mole of P4S3 at a constant pressure of 1 atm. She wrote the following thermochemical equation:
P4S3(s) + 8O2(g) → P4O10(s) + 3SO2(g); ∆Ho = –3651 kJ
Calculate the standard enthalpy of formation of P4S3, using this student’s result and the following standard enthalpies of formation: P4O10(s), –3009.9 kJ/mol; SO2(g), –296.8 kJ/mol. How does this value compare with the value given in Appendix C?