Nitrogen-15 Fractionation in the Thermal Decomposition of Nitrous Oxide of Natural Isotopic Composition

In the region of pressure 0 to 500 mrn approximately to the equation the thermal decomposition of nitrous oxide conforms approximately to the equation k = an /1 + a'n + bn , where k is the form al first-order rate constant, — (1/n) d n /d t , n the initial concentration and a, a' and b are nearly constant. Above about 100 m m this expression approximates to k = A + bn , which holds up to several atmospheres. Fresh and more detailed experiments have once again disproved the suggestion that the first term in these expressions is due to a surface reaction. (In certain states of reaction vessels, made of a particular brand of silica, a surface reaction may appear but is immediately recognizable by special criteria, and can be eliminated.) Detailed study of the formation of nitric oxide in the course of the decomposition, and of the effect of inert gas upon this process, shows that side reactions involving oxygen atoms, chain reactions and catalysis by nitric oxide play only minor parts in determining the shape of the k-n curve. The form of this curve, which is an inherent character of the reaction N 2 O = N 2 + O, raises theoretical questions of considerable interest.

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The kinetics of the oxidation of ammonia by nitrous oxide

Australian Journal of Chemistry ◽

10.1071/ch9640202 ◽

1964 ◽

Vol 17 (2) ◽

pp. 202 ◽

Cited By ~ 2

Author(s):

TN Bell ◽

JW Hedger

Keyword(s):

Thermal Decomposition ◽

Nitrous Oxide ◽

Free Radical ◽

Rate Equation ◽

Radical Mechanism ◽

15N Isotope ◽

Free Radical Mechanism ◽

Products Of Reaction ◽

Kinetics Of ◽

Decomposition Of Nitrous Oxide

Ammonia is oxidized by nitrous oxide smoothly and homogeneously at temperatures between 658 and 730� and total pressures up to 250 mm. The products of reaction, nitrogen, water, and hydrazine are accounted for by a free-radical mechanism initiated by oxygen atoms which result from the thermal decomposition of nitrous oxide. Ammonia labelled with the 15N-isotope was used to distinguish between the nitrogen formed from the nitrous oxide and that from the ammonia. The kinetics follow an empirical rate equation, �� Rate = k'[N2O]1.56 + k"[N2O]0.61[NH3]. This is of a form which shows the importance of the ammonia molecule participating in the activation of nitrous oxide through bimolecular collision. Assigning a collisional efficiency of unity for like N2O-N2O collisions, the efficiency of ammonia in the process �� NH3 + N2O → NH3 + N2O* is determined as 0.85.

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Interpretation of the Data on the Thermal Decomposition of Nitrous Oxide

The Journal of Chemical Physics ◽

10.1063/1.1748328 ◽

1951 ◽

Vol 19 (6) ◽

pp. 663-667 ◽

Cited By ~ 50

Author(s):

Harold S. Johnston

Keyword(s):

Thermal Decomposition ◽

Nitrous Oxide ◽

Decomposition Of Nitrous Oxide

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The thermal decomposition of ethyl ether on the surface of Platinum

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

10.1098/rspa.1930.0122 ◽

1930 ◽

Vol 128 (808) ◽

pp. 451-458 ◽

Cited By ~ 6

Keyword(s):

Thermal Decomposition ◽

Nitrous Oxide ◽

Diethyl Ether ◽

Ethyl Ether ◽

Hydrogen Iodide ◽

Unimolecular Reaction ◽

Homogeneous Reaction ◽

Bimolecular Reactions ◽

Gas Reactions ◽

Decomposition Of Nitrous Oxide

It is of considerable interest to compare the velocities of homogeneous and heterogeneous gas reactions. In general homogeneous bimolecular reactions tend to become unimolecular in the presence of a catalyst, and the heat of activation falls to about one-half. This has been shown to be the case in the decomposition of nitrous oxide, hydrogen iodide, and ammonia. The question arises as to what is the effect of a catalyst on a homogeneous unimolecular reaction. The decomposition of gaseous diethyl ether was chosen for investigation on account of its simplicity; and an attempt has been made to compare the heterogeneous decomposition on the surface of platinum with that of the homogeneous reaction which has been investigated by Hinshelwood.

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