AI Article Synopsis
- The study measured the reaction rate of alpha-pinene with ozone across a temperature range of 243 K to 303 K in a large controlled chamber.
- An Arrhenius expression was established, showing a pre-exponential factor of (1.4 +/- 0.4) x 10(-15) cm3 s(-1) and a temperature coefficient of (833 +/- 86) K.
- The findings align closely with IUPAC recommendations at 298 K, but differ significantly at lower temperatures, highlighting implications for tropical regions where alpha-pinene can be transported to cooler atmospheric layers.
Article Abstract
The absolute rate coefficient for the reaction of alpha-pinene with ozone was determined in the temperature range between 243 K and 303 K at atmospheric pressure. In total, 30 experiments were performed in the large (85 m3) temperature-controlled simulation chamber AIDA, where the concentrations of the reactants ozone and alpha-pinene were measured directly. An Arrhenius expression for the alpha-pinene + ozone reaction was derived with a pre-exponential factor of (1.4 +/- 0.4) x 10(-15) cm3 s(-1) and a temperature coefficient of (833 +/- 86) K. This rate coefficient is in good agreement (-5%) with the current IUPAC (IUPAC 2007) recommendation at 298 K. The IUPAC recommendation is significantly larger (+27%), around 243 K where the recommended values were extrapolated from higher temperatures. This finding is relevant for tropical regions where strong updrafts can rapidly transport reactive hydrocarbons like alpha-pinene from the boundary layer into the cold regions of the free troposphere.
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| http://dx.doi.org/10.1039/b813407c | DOI Listing |
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