Contributions to the Data on Theoretical Metallurgy: [Part] 11. Entropies of Inorganic Substances: Revision (1948) of Data and Methods of Calculation Page: 62
The following text was automatically extracted from the image on this page using optical character recognition software:
62 CONTRIBUTIONS TO DATA ON THEORETICAL METALLURGY
MgC12.4H20(c). There are calculated S.12= 5.73 (extrapolated),
S298.16-S0.12:--57.35 (measured), and S298.16- 63.1 0.7.
In addition, Kelley and Moore (293) (540-2960) measured the
heat capacity of MgCl2.6H20(c). There are obtained S50.12- 8.76
(extrapolated), S29s.16-S50.12= 78.75 (measured), and S98.16= 87.5
For MgCl(g), there is estimated S9;s.16 =55.00.5. This is based
upon w=464 (212), quantum weight of the ground statee=2, and an
assumed I= 82 X 10-40.
Chromite.-Shomate (425) (540-2960) measured the heat capacity
of MgCr204(c). The data yield S3.09- 1.63 (extrapolated), S298.16-
S3.09=23.71 (measured), and S209.16=-25.3 0.2.
Fluoride.-The heat capacity of MgF2(c) was measured by Todd
(486) (540-2970). The data yield S,.0--0.54 (extrapolated),
S098s.1-S1.0 13.14 (measured), and S2's.16= 13.68 0.07.
Molecular-constant data (212), I-54.2X 10-40, w= 687, and
quantum weight-2 for the ground state, lead to S+r,29.16 , 51.13,
80.29.1 -0.32, Se,298.16=1.38, and S9s.-52.80.5 for Mg F(g).
Hydrides.-Molecular-constant data (212) are available for MgH(g)
and MgD(g). For the former, 1-4.8X 10-40 and w=1,463; for the
latter, I=9.24 X10-40 and w=1,062. Both have a quantum weight
of 2 for the ground state.
For MglH(g), S+r,298 .1644.720, S,298.16= 0.011, Se,296.16-1,378, and
S2098.16= 46.11 0.10.
The corresponding values for MgD(g) are St+r,298.16= 46.133,
Sv,298.16= 0.072, Sea29s.i-- 1.378, and S,s.1=47.58 10.10.
Hydroxide.-Giauque and Archibald (173) (220-3210) measured
the heat capacity of Mg(OH)2(c). Their caluclations give S98.16=
15.09, of which 0.033 is extrapolation below 21.10. The uncertainty
should not exceed 0.05 unit.
Iodide.-The vibration frequency of the MgI(g) molecule has been
reported (212) as 312 cm.-. This value, quantum weight of 2 for
the ground state, and an estimated value of the moment of inertia,
I= 172X 10-0, lead to S2s.1 59.9 0.5.
Nitrate.-Shomate and Kelley (4 5) (540-2970) measured the heat
capacity of Mg(N03)2(c). There are computed, Sl3.09=4.09 (extra-
polation), S98.16_-S 3.09-35.06 (measured), and Ss98.16=39.20.4.
Silicates.-The heat capacity of MgSiO1 (clinoenstatite) was
measured by Kelley (285) (520-2960) and Wagner (496) (210-360).
The data of Wagner appear to be too high and only those of Kelley are
used in obtaining S0.120.49 (extapolation), S's.1 -S500.12= 15.73
(measured), and S298.16 16.22 0.10.
Kelley(285)(53'-2950) also measured the heat capacity of Mg2SiO4(c).
There are computed S0.12- 0.60 (extrapolation), S' s.1s-S0.12=22.15
(measured), and Sios.16 22.75 0.2.
Sulfate.-The heat capacity of MgSO4(c) was measured by Moore
and Kelley (365) (530-2960). There are obtained S0.12 =1.10 (extra-
polation), Ss98.16--S0.12-20.78 (measured), and Sys.16= 21.9 0.2.
Titanate.-Shomate (430) (520-2970) measured the heat capacity
of MgTiO3(c). His data yield S2.oo= 0.45 (extrapolation), S98s.-16
S2.00=-17.37 (measured), and S ,98.16= 17.82 -0.10.
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
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/m1/66/: accessed April 23, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.