Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-25T02:21:23.822Z Has data issue: false hasContentIssue false
  • English
  • Français

The specific heat of carbon dioxide and the form of the CO2 molecule

Published online by Cambridge University Press:  24 October 2008

W. H. McCrea
W. H. McCrea
Affiliation:
Trinity College
Get access Rights & Permissions [Opens in a new window]

Summary

Two alternative forms of the CO2 molecule have been suggested by various authors who have discussed the band spectrum data. The specific heat curves based on these models are considered here. It is found that neither is quite satisfactory over the whole range of temperature and we discuss the difficulties for the low temperature and high temperature portions separately. In order to get agreement for low temperatures we find it necessary to introduce a further hypothesis about the molecular model which also seems to explain one or two outstanding difficulties in interpreting the fine structure of the bands. This assumption does not make any difference at higher temperatures where we show the error in one of the curves to be of the order we should expect to be accounted for by a centrifugal stretching of the molecule.

Type
Research Article
Information
Mathematical Proceedings of the Cambridge Philosophical Society , Volume 23 , Issue 8 , October 1927 , pp. 890 - 900
Copyright
Copyright © Cambridge Philosophical Society 1927

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

* Verh. d. D. phys. Ges. XVI, p. 737 (1914).Google Scholar

† Phil. Mag. I, p. 195 (1926).Google Scholar

‡ Zs. f. Phys. 36, p. 641 (1926).CrossRefGoogle Scholar

§ Zs. f. Phys. 37, p. 714 (1926).CrossRefGoogle Scholar

‖ Bjerrum, (l.c.) obtains two solutions to the equations of motion—the present one and another—and he could not decide which should be taken.Google Scholar

Deinnison, , Nature, 02. 26, 1927, p. 316.Google Scholar

* Kemble, and van Vleck, , Phys. Rev. XXI, p. 653 (1923).CrossRefGoogle Scholar

* The second term on the R.H.S. is sometimes given as which is sufficient, but (6) is, in fact, true.

* The corresponding equation for a homopolar diatomic molecule is given by Hund, , Zs. f. Phys. 42, p. 118 (1927).CrossRefGoogle Scholar

* For example, .

† Zt. f. Phys. 38, p. 137 (1926).CrossRefGoogle Scholar

* Schaefer and Philipps remark that the band which they tabulate as 2ν2 – ν1 may alternatively be given as ν2 + 2ν3. It is a double doublet and forms the only possible exception to what is said above. On our theory the two lines of the n series in ν2, for example, will be due to switches in n of 1→2 and 2→1 (requiring again C ≅ 1·5 × 10−40) and we still cannot explain why more lines of the series are not observed.

† See, for example, Born, Atommechanik, p. 140 et seq.Google Scholar

‡ For the values of these quantities see Kemble and van Vleck.

* Proc. Nat. Acad. Sci. 12, p. 602 (1926). The method of the old Quantum theory is used but the new theory is bound to give a similar solution.CrossRefGoogle Scholar

* Zahn, , Phys. Rev. 27, p. 455 (1926);CrossRefGoogle ScholarWeigt, , Phys. Zs. 22, p. 643 (1921);Google ScholarJona, , Phys. Zs. 20, p. 14 (1919).Google Scholar [My attention has been called by Mr F. I. G. Rawlins to some work by Kliefoth, , Zs. f. Phys. 39, p. 402 (1926), who obtains a non-zero moment agreeing with Weigt's but by a different method. (Added in proof.)]CrossRefGoogle Scholar