The heterogeneous chemical kinetics of NO3 on atmospheric mineral dust surrogates

2005 ◽  
Vol 7 (17) ◽  
pp. 3150 ◽  
Author(s):  
Federico Karagulian ◽  
Michel J. Rossi
Keyword(s):  
Chemical Kinetics ◽  
Mineral Dust ◽  
Heterogeneous Chemical ◽  
Kinetics Of

scholarly journals The heterogeneous chemical kinetics of N<sub>2</sub>O<sub>5</sub> on CaCO<sub>3</sub> and other atmospheric mineral dust surrogates

2005 ◽  
Vol 5 (5) ◽  
pp. 10369-10408
Author(s):  
F. Karagulian ◽  
C. Santschi ◽  
M. J. Rossi
Keyword(s):  
Gas Phase ◽  
Chemical Kinetics ◽  
Mineral Dust ◽  
Saharan Dust ◽  
Molecular Flow ◽  
Flow Conditions ◽  
Heterogeneous Chemical ◽  
Powder Samples ◽  
Kinetics Of ◽  
Hydrolysis Of

Abstract. Uptake experiments of N2O5 on several mineral dust powder samples were carried out under continuous molecular flow conditions at 298±2 K. At [N2O5]0=(4.0±1.0)×1011 cm−3 we have found γss values ranging from (3.5±1.1)×10−2 for CaCO3 to (0.20±0.05) for Saharan Dust with γss decreasing as [N2O5]0 increased. We have observed delayed production of HNO3 upon uptake of N2O5 for every investigated sample owing to hydrolysis of N2O5 with surface-adsorbed H2O. At high and low [N2O5] Arizona Test Dust and Kaolinite turned out to be the samples to produce the largest amount of gas phase HNO3 with respect to N2O5 taken up. In contrast, the yield of HNO3 for Saharan Dust and CaCO3 are lower. On CaCO3 the disappearance of N2O5 was also accompanied by the formation of CO2. For CaCO3 sample masses ranging from 0.33 to 2.0 g, the yield of CO2 was approximately 42–50% with respect to the total number of N2O5 molecules taken up. The reaction of N2O5 with mineral dust and the subsequent production of gas phase HNO3 leads to a decrease in [NOx] which may have a significant effect on global ozone.

GAS-PHASE AND HETEROGENEOUS CHEMICAL KINETICS OF THE TROPOSPHERE AND STRATOSPHERE

1996 ◽  
Vol 47 (1) ◽  
pp. 327-367 ◽  
Author(s):  
Mario J. Molina ◽  
Luisa T. Molina ◽  
Charles E. Kolb
Keyword(s):  
Gas Phase ◽  
Chemical Kinetics ◽  
Heterogeneous Chemical ◽  
Kinetics Of

CHEMICAL KINETICS OF WEATHERING IN YOUNG ANDISOLS FROM NORTHEASTERN JAPAN USING SOIL AGE NORMALIZED TO 10°C

Soil Science ◽  
1993 ◽  
Vol 155 (1) ◽  
pp. 53-60 ◽  
Author(s):  
SADAO SHOJI ◽  
MASAMI NANZYO ◽  
YASUHITO SHIRATO ◽  
TOYOAKI ITO
Keyword(s):  
Chemical Kinetics ◽  
Northeastern Japan ◽  
Soil Age ◽  
Kinetics Of

Vulcanization of Elastomers. 23. The Chemical Kinetics of Vulcanization Reactions and The Physical Properties of The Vulcanizates. I

1960 ◽  
Vol 33 (2) ◽  
pp. 335-341
Author(s):  
Walter Scheele ◽  
Karl-Heinz Hillmer
Keyword(s):  
Activation Energy ◽  
Physical Properties ◽  
Chemical Kinetics ◽  
Kcal Mole ◽  
First Order ◽  
Equilibrium Swelling ◽  
Kinetics Of ◽  
Kinetics Of Vulcanization ◽  
Limiting Value ◽  
Good Agreement

Abstract As a complement to earlier investigations, and in order to examine more closely the connection between the chemical kinetics and the changes with vulcanization time of the physical properties in the case of vulcanization reactions, we used thiuram vulcanizations as an example, and concerned ourselves with the dependence of stress values (moduli) at different degrees of elongation and different vulcanization temperatures. We found: 1. Stress values attain a limiting value, dependent on the degree of elongation, but independent of the vulcanization temperature at constant elongation. 2. The rise in stress values with the vulcanization time is characterized by an initial delay, which, however, is practically nonexistent at higher temperatures. 3. The kinetics of the increase in stress values with vulcanization time are both qualitatively and quantitatively in accord with the dependence of the reciprocal equilibrium swelling on the vulcanization time; both processes, after a retardation, go according to the first order law and at the same rate. 4. From the temperature dependence of the rate constants of reciprocal equilibrium swelling, as well as of the increase in stress, an activation energy of 22 kcal/mole can be calculated, in good agreement with the activation energy of dithiocarbamate formation in thiuram vulcanizations.

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