Reaction between NO3 and CHO2 in Air. A Determination of the Rate Constant at 295 +- 2K

THE REACTION BETWEEN NO3 AND CH2O WAS STUDIED IN A 450-L GLASS TEFLON CHAMBER USING INFRARED FT-SPECTROSCOPY AS THE ANALYTICAL TECHNIQUE. NO3 WAS OBTAINED IN EQUILIBRIUM WITH N2O5NINTRODUCED FROM EVAPORATION OF THE SOLID PHA- SE INTO THE CELL OR GENERATED IN THE CELL ITSELF BY REACTING NO2 WITH O3. EX- PERIMENTS WERE PERFORMED IN BOTH CASES AT 295 +- 2 K AND 740 TORR PRESSURE IN PURIFIED AIR. C13H2O WAS USED TO AVOID SPURIOUS EFFECTS ON THE MEASURED CO; C13O18 WAS INTRODUCED TO ESTIMATE THE OH RADICAL CONCENTRATION IN THE SYSTEMS FRFROM THE BUILD-UP OF THE OXIDATION PRODUCT O16C13O18, C13H2O, C13O16, N2O5, HNO3, O3, NO2 AND HCOOH TIME-DEPENDENT CONCENTRATIONS WERE MEASURED AND THE DA- TA FITTED ON THE BASIS OF A MODEL INVOLVING 31 REACTIONS WITH THE FACSIMILE COM-PUTER PROGRAMME. A RATA CONSTANT FOR THE REACTION NO3 + CH2O EQUAL TO (5.4 +- 1.1) X10-16 CM3 MOLEC-1 S-1 AT 295 +- 2 K AND TORR HAS BEEN OBTAINED. SIGNIFI- CANT DIFFERENCES HAVE BEEN FOUND BETWEEN THE MEASURED CONCENTRATIONS OF OH AND HCOOH WITH RESPECT TO THOSE PREDICTED BY THE MODEL. IN THE FRAME OF THIS STU- DY, THE ABSOLUTE STRENGHT OF THE V6 BAND OF HC12OOH (1045-1135-1) HAS BEEN MEA- SURED TO BE EQUAL TO (3.48 +- 0.5)X10-17 CM1MOLEC-1

RESTELLI Giambattista;  OTTOBRINI Giuseppe; 

1995-03-15

JRC5089

https://publications.jrc.ec.europa.eu/repository/handle/JRC5089,