The title reactions were studied using laser flash photolysis in conjunction with vacuum ultraviolet laser-induced fluorescence techniques: Separate monitoring of the two spin orbit states, Cl*(P-2(1/2)) and Cl(P-2(3/2)), was used to measure the kinetics of the chemical reactions of Cl(P-2(3/2)) and Cl*(P-2(1/2)), and physical quenching of Cl*(P-2(1/2)). The rate constants for chemical reactions of Cl*(P-2(1/2)) atoms with C3H8, n-C4H10, and i-C4H10 are approximately 30% of those for Cl(P-2(3/2)) atoms. There was no observable chemical reaction of Cl*(P-2(1/2)) atoms with C3D8 and C2H6 (<17% of rights reserved. Cl(P-2(3/2)) reaction rate).