The rate coefficient for the reaction of Cl atoms with (1) H2O and of Cl-2(-) radical anions with (2) H2O and (3) OH- have beendetermined using laser photolysis for the generation of Cl/Cl-2(-) and long path laser absorption for the time resolved detection of Cl-2(-).The following results were obtained: k(1) = (2.3 +/- 0.6).10(5) s(-1), k(2)<610 s(-1) and k(3) = (4.0+/-0.6).10(6) M-1 s(-1). It isconcluded that the lifetime of Cl/Cl-2(-) in aqueous solution strongly depends on the Cl- content and on pH.