Contributions to the Data on Theoretical Metallurgy: [Part] 11. Entropies of Inorganic Substances: Revision (1948) of Data and Methods of Calculation Page: 39
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ENTROPIES OF INORGANIC SUBSTANCES AT 298.160K.
tion), AS0.4= 0.89 (for the extra heat capacity at the "hump"), S90.8-
S10o=12.43 (crystals less extra heat capacity at the "hump"), AS0.s=
224.0 27 1,988
90.6 =2.47 (fusion), Sln.7-SOo.=-2.70 (liquid), AS11.7-111.717.80
(vaporization at 1 atm. pressure, from the vapor-pressure data of
Stock, Henning, and Kuss (471)), and S989s.6-Sj .7= 7.91 (gas). The
sum is S298.16= 44.51 0.2.
A later calculation by Frank and Clusius (161) yields So0.6= 13.66
(crystals), AS o0.62.47 (fusion), S9.4-So0.-= 1.21 (liquid), AS99.54-
20.45 (vaporization at 246.13 mm. pressure), AS9.s54= -2.24 (com-
pression from 246.13 mm. to 1 atm. pressure), and AS99.54=0.08 (cor-
rection to ideal gas state). To bring the gas to 298.160 requires an
entropy increment of S298.16-S99.54=8.83 (gas). The sum is S298.1-6
44.46 0.2, virtually identical with the other calculation.
From molecular constants (311) 11=12=13=5.27X 10-4o, 1-
1,305 (3), 2= 1,520 (2), o3=2,915 (1), w4=-3,020 (3), and symmetry
number= 12, there are computed S+r, 298.18=-44.37, S0. 298.16-0.10, and
S98.6-=44.470.10. This last value is adopted.
Carbonic Acid and Its Ions.-Latimer, Pitzer, and Smith (325) re-
ported S298.16s=45.1 0.7 for H2CO3 (aq.) from data for the reaction
CO(g)+H20 (1) =H2CO3(aq.).
The same authors find S98.1-=22.2 +0.8 for HCOa-(aq.) from data
for the reaction H2CO3(aq.)-=-H+(aq.)+HCO3-(aq.).
They also give S2098.18- -13.0 1.0 for C03--(aq.), computed from
thermal data for the reaction HCO3-(aq.)=-H+(aq.)+C03--(aq-.)
Cyanate Ion.-The National Bureau of Standards tables (370) list
S,29.1 ,=31.1 for CNO-(aq.).
Oxalate Ion.-From data for the reaction CaC204-H20(c)= Ca++
(aq.)+C204--(aq.)+H20(1), Latimer, Pitzer, and Smith (325) ob-
tained S298.16=9.6 +1 for C204--(aq.).
Element.-Lewis and Gibson (331) have computed the entropy of
Ce(c) from Dewar's (126) value of the mean heat capacity between
200 and 770. Their method consisted essentially of correcting Dewar's
reported value by the factor 1.085 and then computing 0D for a Debye
function. They obtained S298.1-= 13.8, in which the error may be as
much as +0.8. No other low-temperature heat-capacity values of
Ce(c) are available except those of Simon and Ruhemann (441)
(710-720) on an impure sample. The heat capacity at this temperature
is too high (6.14) for obtaining OD.
Available energy-level data for Ce(g) (364) add 7.36 to the entropy
given by the Sackur equation, to make S29s.1 =48.09 0.05.
Element.-The entropy of Cs(g), calculated from the Sackur equa-
tion with R In 2 added, is SO98.16=41.95 0.01.
The entropy of sublimation of Cs (c) has been computed from vapor-
pressure and heat-capacity data (270) as AS298.16=22.13. This value
and the entropy of Cs(g) leads to the estimate S298.16= 19.81.0 for
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Kelley, K. K. Contributions to the Data on Theoretical Metallurgy: [Part] 11. Entropies of Inorganic Substances: Revision (1948) of Data and Methods of Calculation, report, 1950; Washington D.C.. (https://digital.library.unt.edu/ark:/67531/metadc12637/m1/43/: accessed April 19, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.