Cyanogen Flames and the Dissociation Energy of N2

The behavior of cyanogen flames under a variety of conditions has been observed. Because of the relatively high stability of cyanogen, the behavior is considerably different from that of hydrocarbon flames. Because of the high stability of the combustion products, CO and N2, the flame temperature can reach temperatures above 4800°K. Thus the cyanogen‐oxygen flame is the hottest natural flame known.Spectroscopic observations have been made of both the reaction zone and the mantle of completely combusted gases. Rotational and vibrational temperature measurements using the CN violet system have indicated that the reaction zone is not in thermal equilibrium but that the mantle is in thermal equilibrium. Comparison of the calculated flame temperatures based on different heats of dissociation of N2 with the observed mantle temperatures has fixed DN2=9.764±0.005 ev and DCN=8.2±0.2 ev.

[1]  L. Brewer,et al.  The Heat of Formation of CN and the Dissociation Energies of N2 and C2N2 , 1951 .

[2]  A. G. Gaydon,et al.  Spectroscopic studies of low-pressure flames - V. Evidence for abnormally high electronic excitation , 1951, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[3]  A. G. Gaydon,et al.  Spectroscopic studies of low-pressure flames III. Effective rotational temperatures and excitation mechanism for C2 bands , 1950, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[4]  J. R. Arthur.  Some Reactions of Atomic Hydrogen in Flames , 1950, Nature.

[5]  H. G. Wolfhard,et al.  A New Technique for the Spectroscopic Examination of Flames at Normal Pressures , 1949 .

[6]  M. Feast.  The CN Tail Bands emitted by the Carbon Arc in Air , 1949 .

[7]  A. G. Gaydon,et al.  The spectra of flames containing oxides of sulphur , 1947, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[8]  A. G. Gaydon,et al.  The spectra of chilled hydrocarbon flames , 1942, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[9]  L. Gerö,et al.  Dissociation energy of the CN molecule , 1938 .

[10]  H. Maecker,et al.  Temperaturbestimmung an frei brennenden Kohlelichtbögen mit Hilfe der CN-Banden , 1937 .

[11]  L. Ornstein,et al.  Untersuchungen über das negative Stickstoff bandenspektrum , 1928 .