AbstractUsing a relative rate technique, rate constants have been determined for the gas phase reactions of Cl atoms with a series of organics at 296 ± 2 K and atmospheric pressure of air. Using a rate constant of 1.97 × 10−10cm3molecule−1s−1for the reaction of Cl atoms withn‐butane, the following rate constants (in units of 10−11cm3molecule−1s−1) were obtained: ethane, 6.38 ± 0.18; propane, 13.4 ± 0.5; isobutane, 13.7 ± 0.2;n‐pentane, 25.2 ± 1.2; isopentane, 20.3 ± 0.8; neopentane, 11.0 ± 0.3;n‐hexane, 30.3 ± 0.6; cyclohexane, 31.1 ± 1.4; 2,3‐dimethylbutane, 20.7 ± 0.6;n‐heptane, 34.1 ± 1.2; acetylene, 6.28 ± 0.18; ethene, 10.6 ± 0.3; propene, 24.4 ± 0.8; benzene, 1.5 ± 0.9; and toluene, 5.89 ± 0.36. These data are compared and discusse