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Author Knight, H. T. ♦ Rink, J. P.
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ CHEMICAL REACTIONS ♦ CYANIDES ♦ DECOMPOSITION ♦ DENSITY ♦ ENERGY ♦ FORMATION HEAT ♦ FREE RADICALS ♦ GRAPHITE ♦ MEASURED VALUES ♦ NITROGEN ♦ PRESSURE ♦ SHOCK WAVES ♦ VELOCITY ♦ X RADIATION
Abstract Density ratios across shock waves in a 0.85 Kr + 0.15 C/sub 2/N/sub 2/ mixture at an initial pressure of 50 mm Hg and room temperature, were determined with an x-ray densitometer as a function of shock velocity. The heat required to dissociate cyanogen into two CN radicals D(C/sub 2/N/sub 2/) was determined to be 145 plus or minus 6 kcal/mole by comparing the experimental data with curves of density ratio vs shock velocity calculated as a function of D(C/sub >/N/sub 2/). Dissociation energies of 174 plus or minus 3 kcal/mole for CN and 129 plus or minus 3 kcal/mole for HCN forming H and CN, and a heat of formation of 109 plus or minus 3 kcal/ mole for CN, were obtained by the application of Hess's law to the appropriate chemical reactions using the value of D(C/sub 2/N/sub 2/) and the currently accepted values for the dissociation enengy of nitrogen (225 kcal/mole) and the heat of sublimation of graphite (170 kcal/mole). The value of D(HCN) was confirmed by annalogous density-velocity measurements on shock waves in a 0.85 Kr plus or minus 0.15 HCN mixture. A rate constant for the recombination of CN to form C/sub 2/N/sub 2/ at 2900 deg K was deduced from the variation of density with time behind the shock. The value obtained was the order of 1 plus or minus 10/sup 9/(mole/liter)/sup -2/ sec/sup -1/. (auth)
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 1961-07-01
Publisher Department Los Alamos Scientific Lab., N. Mex.
Journal Journal of Chemical Physics
Volume Number 35
Organization Los Alamos Scientific Lab., N. Mex.


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