Contributions to the Data on Theoretical Metallurgy: [Part] 11. Entropies of Inorganic Substances: Revision (1948) of Data and Methods of Calculation Page: 73
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ENTROPIES OF INORGANIC SUBSTANCES AT 298.16 0K.
The value S98.16=-49.01 0.01 is adopted for 02(g).
The entropy of monatomic O(g) is obtainable from the Sackur
equation and spectroscopic data (364). At 298.160, the only states
to be considered are 3P2, 3P1, and 3P0, which have term values 0,
158.17, and 226.78 cm.-1, and quantum weights 5, 3, and 1, respec-
tively. These states contribute 4.214 and the translational entropy
is 34.262, making S98.16=38.480.01 for O(g).
Ozone.-Shand and Spurr (420) have reported dimensions of the
03(g) molecule that yield the moments of inertia 1=-67.6X 10-40
12=5.60X 10-40, and '2=73.2X 10-40. The vibration frequencies are
w,=1,110(1), &w2=705(1), and 3=1,043(1). These values result in
S+r,298.16=56.413, S;,298.16-0.437, and S2098.16-56.85 0.10.
Neutral Hydroxyl.-Johnston and Dawson (230) computed S'9.16=
43.90 0.02 for neutral OH(g) from spectroscopic data. From molec-
ular constants (212), 1=1.484X10-4o and -3,650, and the term
values 0 and 140 cm.- for the two energy states (both of quantum
weight 2) involved at 298.160, there are computed S+r7,298.16=41.196,
S298.6=0.000, S ,298.16-2.653, and S 9.18-43.85. Johnston and
Dawson's result is selected.
Hydroxyl Ion.-Latimer, Pitzer, and Smith (325) report S29s.16=
-2.49+0.06 for OH-(aq.) from thermal data for the reaction
H20 (1)= H+ (aq.) + OH- (aq.).
Element.-The heat capacity of Pd (c) was measured by Clusius
and Schachinger (104) (130-2690) and Pickard (386) (2.50-220).
The entropy is computed to be S298.16-9.030.05, of which only
0.003 is extrapolation below 2.50.
The entropy of Pd(g), obtained from the Sackur equation, is S98s.-6=
Element.-The entropy of P2(g) is obtainable from molecular-
constant data, 1=92.5X10-40 (213) and w0777.6 (212). There are
computed S+r,298.16 51.885, S ,298.16 0.226, and S2098s.16-52.11
0.10. Yost and Anderson (506) calculated a virtually identical value,
S198.16=52.0, and Stevenson and Yost (470) reported S298.16-52.15.
Anderson and Yost (26) have given 2.21 X 10-8 cm as the inter-
atomic distance in the tetrahedral P4(g) molecule and 372 (2), 463 (3),
and 607 (1) as the vibration frequencies. The dimensional value
corresponds to I, 12 13 - 251 X 10-40. There are computed S+r,298.16
=61.987, S;,298.16-4.863, and S;98.16-66.850.5.
The entropy of P(g) is calculated from the Sackur equation with
R In 4 added to account for the quantum weight of the ground state
The result is S29s.81638.99 10.01.
The entropy of sublimation of P(c) (white) to P4(g) was given as
AS098s.16 24.59 by Kelley (270). Combination of this result and the
value for P4(g) leads to S298.16-10.60.5 for P(c) (white), in agree-
ment with the value, 10.55, calculated by Anderson and Yost (26).
Latimer (315) has estimated S2098.16-7.0 for P(c) (violet). This
value is checked by combining the entropy of sublimation of P(c)
(violet), AS29s.16-37.11 (270) and the entropy of P4(g). The result
is S298.16- 7.4 0. 5.
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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/m1/77/: accessed April 26, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.