Wednesday, February 14, 2007

The stangest flame (ozone-oxygen).

Searching for the ozone flames information, I found the strangest flame ever: pure ozone-oxygen (Streng A.G.; Grosse A.V. The pure ozone to oxygen flame. JACS 1957, 79(6), 1517-1518). Quote:

By using pure ozone, containing less than a few parts per million of organic impurities, as described originally by C. E. Thorp we have been able to burn ozone-oxygen mixtures to oxygen in the entire range from 17-100 mole % 03. The all-Pyrex glass apparatus was extremely simple; it consisted of a narrow glass gasholder, from which any desired mixture of 03-02 or pure 03 could be delivered at any predetermined rate, by simple displacement with water. From the gasholder the gas mixture went to a Pyrex glass, quartz, or aluminum tip. Stopcocks greased with CnF2n+2 or Kel-F, were used. The burning velocities were determined by the standard schlieren method. In the range of 17 to about 50 mole % 03 , the flame cannot be observed visually, but can be seen very easily on the screen of the schlieren apparatus. The flame is visible above this range. Pure 100% ozone burns with a faint, non-luminous flame, blue in color, with a typical pink cast. The experimental burning velocities, at 298°K. and 1.0 atm. pressure, are shown in Fig. 1.
The ozone flame is of particular theoretical interest since it is the simplest flame imaginable. Outside of the “fuel” O3 and the “product of combustion” 02 , the only possible intermediates are oxygen atoms.

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