Reference Label | Details |
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Rossini 1939 | F. D. Rossini, J. Res. Natl. Bur. Stand. 22, 407-414 (1939) Heat and Free Energy of Formation of Water and of Carbon Monoxide |
Rossini 1931a | F. D. Rossini, J. Res. Natl. Bur. Stand. 6, 37-49 (1931) The Heats of Combustion of Methane and Carbon Monoxide |
Rossini 1931b | F. D. Rossini, J. Res. Natl. Bur. Stand. 7, 329-330 (1931) The Heat of Formation of Water and the Heats of Combustion of Methane and Carbon Monoxide. A Correction |
note CO | Rossini 1932 points out that Rossini 1931a used incorrectly pressure corrections and gives 282938 +- 110 int. J/mol as the correct mean of Table 8 in Rossini 1931a for the enthalpy of combustion of CO at 30° C. In addition, we find that Rossini1931a has used an incorrect correction of -249 J/mol (dyslexic, should have been -294 J/mol) for the H2 impurity. Reworking the values in Rossini 1931a Table 8, results in a mean value of 282892.6 +- 49.0 int. J/mol, after introducing corrections to 30.00° C (-2 J/mol needed only for one measurement, all others are 0) and the correction of -294.4 J/mol for the 0.103% H2 impurity. The difference in the mean compared to Rossini 1932 is entirely attributable to the wrong correction for the H2 impurity. The uncertainty given with our mean is simply one std. dev. For 8 measurements, it should be multiplied by 2.364623 to get the desired 95% confidence limit, resulting in +- 115.9 int. J/mol. (It appears that Rossini is assigning an uncertainty corresponding to the average abs. dev., which is 110.5 J/mol). For comparison, we correct the mean from the table to 25° C using Rossini 1931a value of +7 int. J/mol/K to get 282857.6 int. J/mol, or with a more curent value of 33 (int.) J/mol we get 282859.6 int J/mol. Rossini 1932 combined with Rossini 1931a implies a value of 282903 +- 120 int. J/mol. Converting our reinterpretation of 282892.6 +- 115.9 int. J/mol to to abs. J and to present molecular weight of CO2 (which was used to determine the mass of CO) of 44.0095 from 44.00 results in the enthalpy of combustion at 30° C of 282999.0 +- 115.9 J/mol. Rossini 1939 shows that the correction to ideal gas is -25.2 (int.) J/mol, producing a final value of 282973.8 +- 115.9 abs. J/mol at 303.15 K. |