Bibliography #152,975

Reference Label	Details
Eckman 1929	J. R. Eckman and F. D. Rossini, J. Res. Natl. Bur. Stand. 3, 597-618 (1929) The Heat of Formation of Sulphur Dioxide
note SO2	Eckman 1929 find for the combustion of S 296730 +- 0.061% int. J in Series I and 296820 +- 0.040% (+- are average devs from the mean), and obtain a weighted average of 296790 +- 0.047% int. J. Into this they propagate +-0.029% from the calibration average dev. to obtain +- 0.055% or 165 J. This is then additionally increased to +-0.067% or +- 200 J to final 296790 +- 200 int. J. using a conversion to abs. J of 1.00034 they get 296890 +- 200 abs. J for the molec. weight of SO2 of 64.065. CODATA obviously uses the same weighted average 296790 +- 200 int. J., but uses the factor 1/0.99984 = 1.00016 to obtain 296837 abs. J, and then corrects by 64.059/64.065 to new molec. weight to get 296810 +- 200 J. With the current molec weight of 64.0648, this would be 296837 +- 200 J, but really the amount was determined by Eckman and Rossini primarily as the amount of burned S, with the amount of absorbed SO2 only as a secondary and only approximate check, so the correction by CODATA should have been 32.06 (CODATA)/32.065 (Eckman and Rossini) producing 296791 +- 200 J/mol. We agree with 296790 +- 200 int. J., which after all corrections for units (1/0.99984 = 1.00016 producing 296837 J/mol) and molec. weight (32.066/32.065) becomes 296847 +- 200 J/mol, including a basic unc. connected to the uncert. of 0.02% in atomic weight of S (+-56 J/mol). JANAF 3 has 296842 +- 210 kJ/mol, claiming corrections for m.w. and change in electrical constants; their declared m.w. SO2 is 64.0588 and for S is 32.06; however, their value can be reproduced if one assumes they actually used for SO2 64.066, which correspons to m.w. 32.066 for S and 16 for O current as of 1957 (the table is "last revised in 1961"; the 1961 weights did not appear until 1962). NBS Tables report 296830 J/mol for m.w. of 64.0628 for SO2 (or 32.0640 for S); thir correction for m.w. is correct, via atomic weight of S (extracted from NBS archives; reverse engineering does not give this clearly, since 64.0628/64.065=0.9999657 and 32.064/32.065=0.9999688 in this case); rev. eng. suggests J conversion using 1.0001660.

Reference Label

Details

Eckman 1929

J. R. Eckman and F. D. Rossini, J. Res. Natl. Bur. Stand. 3, 597-618 (1929)
The Heat of Formation of Sulphur Dioxide

note SO2

Eckman 1929 find for the combustion of S 296730 +- 0.061% int. J in Series I and 296820 +- 0.040% (+- are average devs from the mean), and obtain a weighted average of 296790 +- 0.047% int. J. Into this they propagate +-0.029% from the calibration average dev. to obtain +- 0.055% or 165 J. This is then additionally increased to +-0.067% or +- 200 J to final 296790 +- 200 int. J. using a conversion to abs. J of 1.00034 they get 296890 +- 200 abs. J for the molec. weight of SO2 of 64.065. CODATA obviously uses the same weighted average 296790 +- 200 int. J., but uses the factor 1/0.99984 = 1.00016 to obtain 296837 abs. J, and then corrects by 64.059/64.065 to new molec. weight to get 296810 +- 200 J. With the current molec weight of 64.0648, this would be 296837 +- 200 J, but really the amount was determined by Eckman and Rossini primarily as the amount of burned S, with the amount of absorbed SO2 only as a secondary and only approximate check, so the correction by CODATA should have been 32.06 (CODATA)/32.065 (Eckman and Rossini) producing 296791 +- 200 J/mol. We agree with 296790 +- 200 int. J., which after all corrections for units (1/0.99984 = 1.00016 producing 296837 J/mol) and molec. weight (32.066/32.065) becomes 296847 +- 200 J/mol, including a basic unc. connected to the uncert. of 0.02% in atomic weight of S (+-56 J/mol). JANAF 3 has 296842 +- 210 kJ/mol, claiming corrections for m.w. and change in electrical constants; their declared m.w. SO2 is 64.0588 and for S is 32.06; however, their value can be reproduced if one assumes they actually used for SO2 64.066, which correspons to m.w. 32.066 for S and 16 for O current as of 1957 (the table is "last revised in 1961"; the 1961 weights did not appear until 1962). NBS Tables report 296830 J/mol for m.w. of 64.0628 for SO2 (or 32.0640 for S); thir correction for m.w. is correct, via atomic weight of S (extracted from NBS archives; reverse engineering does not give this clearly, since 64.0628/64.065=0.9999657 and 32.064/32.065=0.9999688 in this case); rev. eng. suggests J conversion using 1.0001660.