Reference Label Details
Wachi 1972F. M. Wachi and D. E. Gilmartin, High Temp. Sci. 4, 423-431 (1972)
Heat of Formation and Entropy of C3 Molecule
note CaWachi 1972 have measured by mass spectrometry the equilibrium pressure of C above graphite in the temperature range 2509 - 2753 K (14 points). The pressure has been normalized using Co. From this they obtain 2nd and 3rd Law DeltaH0 values of 170.5 +- 7 kcal/mol and 170.0 +- 0.3 kcal/mol. Our reanalysis yields DeltaG(T) = 719.05 +- 13.66 + T*(-0.157624 +- 0.005197) kJ/mol (uncertainies are 1 std. dev.) At the average temperature 2625 K, DeltaG = 305.29 +- 0.73 kJ/mol. Note that Gurvich TPIS quotes the 2nd and 3rd Law DeltaH values at 298 K as 721 +- 30 kJ/mol and 716 +- 10 kJ/mol. The present analysis implies 2nd and 3rd Law DeltaH298 values of 722 +- 30 kJ/mol and 717.0 +- 0.7 kJ/mol, and DeltaH0 of 716.5 +- 30 kJ/mol (171.2 +- 7 kcal/mol) and 711.5 +- 0.7 kJ/mol (170.1 +- 0.2 kcal/mol).
3rd LawThird law analysis