IUPAC Subcommittee on Gas Kinetic Data Evaluation

Providing evaluated kinetic data on the web since 1999.

IUPAC Subcommittee on Gas Kinetic Data Evaluation

Website: http://www.iupac-kinetic.ch.cam.ac.uk/ See website for latest evaluated data. Datasheets can be downloaded for personal use only and must not be retransmitted or disseminated either electronically or in hardcopy without explicit written permission.

This datasheet last evaluated: 2005-04-15 ; last change in preferred values: 2005-04-15 ; last peer-reviewed publication: 2004-03-09


O + NO2 + MNO3 + M(1) Δ Hο = -208.6 kJ mol-1

Rate Coefficient Data: Low-pressure rate coefficients

Absolute Rate Coefficients

Rate Coefficient (k0) / Temperature / ReferenceTechniques and Comments
cm3molecule-1s-1Kelvin
3×10 -31 (T/300) -1.75 [N 2 ]220–296Burkholder and Ravishankara, 2000PLP (a)
(1.3±0.3)×10 -31 (T/300) -1.5 [N 2 ]300–400Hahn et al., 2000PLP (b)

Relative Rate Coefficients

Rate Coefficient (k0) / Temperature / ReferenceTechniques and Comments
cm3molecule-1s-1Kelvin
(9.2 ± 1)×10 -32 [N 2 ]297Harker and Johnston, 1973RR (c)
(8.0 ± 1)×10 -32 [N 2 ]295Hippler et al., 1975RR (d)

Comments

(a) Oxyygen atoms generated by laser photolysis of NO 2 at 352 nm, NO 3 monitored by long-path diode laser absorption at 662 nm. Measurements were made in N 2 over the pressure range 20–800 Torr; falloff curves were represented with F c = 0.6 and k = 3.75×10 -11 cm 3 molecule -1 s -1 independent of the temperature.

(b) Oxyygen atoms generated by laser photolysis of N 2 O at 193 nm, NO 3 monitored by light absorption at 578 nm. Falloff curves measured at 300 and 400 K in N 2 over the presure range 1–900 bar. Falloff curves represented with F c = 0.71 exp (-T/1700), which corresponds to F c = 0.6 at 300 K, and k = (2.3 ± 0.2)×10 -11 (T/300) 0.24 cm 3 molecule -1 s -1 .

(c) O( 3 P) atoms were generated by the photolysis of NO 2 in the presence of 1 bar of N 2 . NO 2 and N 2 O 5 concentrations were monitored by IR absorption. The measured value of k/k(O + NO 2 ) was evaluated with k(O + NO 2 ) = 9.3×10 -12 cm 3 molecule -1 s -1 . The rate coefficient has been re-evaluated by increasing the measured rate coefficient by 10% to account for a 10% falloff below k 0 , as measured by Gaedtke and Troe (1975).

(d) O( 3 P) atoms were generated by the photolysis of NO 2 at various N 2 pressures. NO 2 was monitored by UV absorption. The measured value of k/k(O + NO 2 ) was evaluated with k(O + NO 2 ) = 9.3×10 -12 cm 3 molecule -1 s -1 , taking N 2 O 5 reactions and falloff effects into account.

Preferred Values

k0cm3molecule-1s-1{1.3-31 N_2[N2] 1.3×10-31±0.30 N_2[N2]   if   T 298 1.3-31 T 300 PlusMinus -1.5 1 N_2[N2]1.3×10-31 (T/ 300 )( -1.5 ±1) N_2[N2]  if   200 T 400

Comments on Preferred Values

The preferred values are from the falloff extrapolations of the absolute rate measurements of Hahn et al. (2000) and the relative rate measurements of Harker and Johnston (1973), Hippler et al. (1975), Gaedtke and Troe (1975), Schuck et al. (1966) and Troe (1969). The discrepancy between the absolute rate measurements below 1067 mbar from Burkholder and Ravishankara (2000) and above 1 bar from Hahn et al. (2000) may be due to difficulties in separating the reactions O + NO 2 O 2 + NO and O + NO 2 + M NO 3 + M with subsequent NO 2 + NO 3 + M N 2 O 5 + M. Because the data from Hahn et al. (2000) are in much better consistency with the relative rate measurements from Harker and Johnston (1973), Hippler et al. (1975), Gaedtke and Troe (1975), Schuck et al. (1966) and Troe (1969), they are preferred here. It should be emphasized that falloff effects are important at atmospheric pressures; these effects are represented with F c = 0.6 and k = 2.3×10 -11 (T/300) 0.24 cm 3 molecule -1 s -1 from the measurements and theoretical analysis of Hahn et al. (2000).

Rate Coefficient Data: High-pressure rate coefficients

Absolute Rate Coefficients

Rate Coefficient (k) / Temperature / ReferenceTechniques and Comments
cm3molecule-1s-1Kelvin
(2.3±0.2)×10 -11 (T/300) 0.24 300–400Hahn et al., 2000PLP (a)

Relative Rate Coefficients

Rate Coefficient (k) / Temperature / ReferenceTechniques and Comments
cm3molecule-1s-1Kelvin
(2.2 ± 0.4)×10 -11 300Gaedtke and Troe, 1975(b)

Comments

(a) See comment (b) for k 0 .

(b) Analysis of the pressure dependence of the quantum yield of NO 2 photolysis between 1 and 1000 bar of N 2 . Measurements of k /k(O + NO 2 O 2 + NO) evaluated with k(O + NO 2 ) = 9×10 -12 cm 3 molecule -1 s -1 .

Preferred Values

kcm3molecule-1s-1{2.3-112.3×10-11±0.2  if   T 298 2.3-11 T 300 0.24 2.3×10-11 (T/ 300 ) 0.24   if   200 T 400

Comments on Preferred Values

The absolute and relative rate measurements of the falloff curve over a very wide pressure range from Hahn et al. (2000) and Gaedtke and Troe (1975), on which the preferred values are based, allow for a reliable extrapolation to the high pressure limit of the reaction. Falloff curves are constructed with F c = 0.6 and k 0 = 1.3 x 10 -31 (T/300) -1.5 [N 2 ] cm 3 molecule -1 s -1 .

References

  • Burkholder, J. B. and Ravishankara, A. R. , J. Phys. Chem. A , 104 , 6752 , 2000.
  • Gaedtke, H. and Troe, J. , Ber. Bunsenges. Phys. Chem. , 79 , 184 , 1975.
  • Hahn, J., Luther, K. and Troe, J. , Phys. Chem. Chem. Phys. , 2 , 5098 , 2000.
  • Harker, A. B. and Johnston, H. S. , J. Phys. Chem. , 77 , 1153 , 1973.
  • Hippler, H., Schippert, C. and Troe, J. , Int. J. Chem. Kinet. Symp. , 1 , 27 , 1975.
  • Schuck, E. A., Stephens, E. R. and Schrock, R. R. , J. Air Pollut. Contr. Assoc. , 16 , 695 , 1966.
  • Troe, J. , Ber. Bunsenges. Phys. Chem. , 73 , 906 , 1969.