Conformational kinetics of methyl nitrite. IV. Bimolecular kinetics at low pressures

Methyl nitrate (CH 3 ONO 2 ) is the most explosive of the nitrate esters, and previous studies have been confined mainly to the slow thermal decomposition, and to the vapour phase explosion at low pressures in closed vessels. A stationary decomposition flame has now been maintained and studied spectrographically. A t low pressures the zones of reaction are clearly separated. From the early stages of the flame strong formaldehyde bands are emitted. This decomposition flame has been successfully simulated in artificial mixtures of methyl nitrite with oxygen. The results obtained are in accord with the preliminary fission of the nitrate molecule in the pre-heat zone of the flame: CH 3 ONO 2 →CH 3 O + NO 2 . The combustion flame of m ethyl nitrate with oxygen, nitric oxide and nitrogen dioxide has also been examined at low pressures. At atmospheric pressure, m ethyl nitrite (CH 3 ONO) has been found to support a decomposition flame of very small burning velocity. However, the combustion of m ethyl nitrite with oxygen at atmospheric pressure is an extremely fast and vigorous flame. It has been observed in both pre-mixed and diffusion systems and information about the changes occurring in it have been obtained by absorption and emission spectroscopy. All the experimental results may be interpreted in terms of two general principles: the reluctance of nitric oxide to react except at high temperatures and pressures and the frequent occurrence in flames of extensive pyrolytic reactions before the main reaction zone is reached.

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Conformational kinetics of methyl nitrite. Temperature dependence of helium collision efficiency

Chemical Physics Letters ◽

10.1016/0009-2614(85)85502-0 ◽

1985 ◽

Vol 122 (1-2) ◽

pp. 175-179 ◽

Cited By ~ 5

Author(s):

J.Paul Chauvel ◽

B.Ri. Friedman ◽

Nancy S. True ◽

Eric D. Winegar

Keyword(s):

Temperature Dependence ◽

Collision Efficiency ◽

Methyl Nitrite ◽

Kinetics Of

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The thermal decomposition of acetaldehyde and the existence of different activated states

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1933.0102 ◽

1933 ◽

Vol 141 (843) ◽

pp. 41-55 ◽

Cited By ~ 16

Keyword(s):

High Pressures ◽

Initial Pressure ◽

Bimolecular Reaction ◽

Bimolecular Reactions ◽

First Order ◽

Straight Line ◽

Gas Reactions ◽

Pass Through ◽

Low Pressures ◽

Kinetics Of

Homogeneous thermal gas reactions were at one time tacitly assumed to possess a definite order, unimolecular and bimolecular reactions, for example, being sharply distinguished. The kinetics of the decomposition of acetalde hyde, CH 3 CHO = CH 4 + CO, over the pressure range of 100 to 400 mm. were found to satisfy the criterion of a bimolecular reaction, namely, that the reciprocal of the time for half change (1/ t 1/2 ) )plotted against the initial pressure ( p 0 ) gave a straight line inclined to the axes. The line, however, did not pass through the origin, as may be seen in fig. 1 of the present paper. This indicated the presence of some first order reaction, the nature of which was not determined. Subsequently, in accordance with the collision theory of activation and deactivation, it was shown that certain reactions, sometimes called quasiummolecular, change their order from the second at low pressures to the first at high pressures. This apparently was the reverse of the behaviour shown by acetaldehyde.

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