The absolute rate coefficients for the hydrogen abstraction reactions from CH3CCl3(k(1)), CH3CCl2F (k(2)), and CH3CClF2 (k(3)) by chlorine atoms in gas phase have been measured as a function of temperature using the discharge flow/mass spectrometric technique (DF/MS). The reactions were investigated under pseudo-first-order conditions with Cl atoms in large excess with respect to the haloethanes. The temperature dependence of the rate coefficients is expressed in the Arrhenius form : k(1)(298-416K) = (2.8-(4.1)(1.7+)) x 10(-12) exp[-(1790 +/- 320)/T], k(2)(299-429K) = (3.0(-1.3)(+2.4)) x 10(-12) exp[-(2220 +/- 150)/T], k(3)(298-438K) = (1.5(-1.0)(+3.1)) x 10(-12) exp[-(2420 +/- 400)/T]. The units of the rate constants are cm(3) molecule(-1) s(-1), and the quoted uncertainties are +/-2 sigma. For understanding the reaction path mechanism of the chlorination of the studied halogen-substituted ethanes, ab initio molecular orbital calculations were performed. Transition state structures were determined. These calculations lead to predictions of preexponential factors in the same order of magnitude of measured values, The ab initio energetics of the reactions were corrected using the ISO-M method, a mixing of isodesmic reactions for obtaining reaction enthalpies and concept of intrinsic energy of Marcus to deduce activation energies. A reasonably good agreement with the experimental values were found.