The bimolecular reaction Cl + C2H5Cl --> HCl + C2H4Cl (1) is studied in the very-low-pressure reactor (VLPR) system at room temperature. Detailed mass spectrometric analysis of simultaneous reactant consumption and product formation rates indicates that the overall mechanism also includes two disproportionation reactions: Cl + C2H4Cl --> HCl + C2H3Cl (2) and 2C(2)H(4)Cl --> C2H5Cl + C2H3Cl (3). Rate constants obtained for these reactions are: k(1) = (8.07 +/- 0.36) x 10(-12), k(2) = (1.18 +/- 0.06) x 10(-11), and k(3) = (1.83 +/-0.15) x 10(-12) cm(3)/(molecule-s). The decrease in the reactivity of C2H5Cl compared with C2H6 reactivity in reaction type (1) correlates well with the electronegativity of the Cl substituent. The decrease points to a dipole-dipole repulsion in the transition state. Preliminary measurement of the reaction of C2H4Cl radical with Cl-2 yields a value of k(5) = (1.7 + 1.0) x 10(-13) cm(3)/(molecule-s).