Rate constants for the reactions of hydroxyl radicals with propane and ethane

Abstract

The kinetics of the reaction OH + C₃H₆→ H₂O + C₂H₇(1) have been studied in a discharge-flow system under first-order conditions. The OH radicals were generated by the reaction of H atoms with NO₂ and the concentration of OH, monitored by resonance fluorescence, was followed as a function of reaction time in a large excess of the alkane. A value of k₁=(7.2±1.1)× 10⁸ dm³ mol^–1 s^–1 at 295 K was obtained.

As a check on the technique the rate constant for the reaction OH + C₂H₆→ H₂O + C₂H₅(2) was determined in a similar fashion. The value obtained, k₂=(1.61±0.24)× 10⁸ dm³ mol^–1 s^–1, is in excellent agreement with other literature values.