Rate of Substitution in the Bromination of Propane Br Br CH3-CH2-CH3 +Br2 hy.125C CH3-CH2一CH2 +CH3-CH-CH3 +HBr primary bromide,3% secondary bromide,97% Relative reactivity six primary hydrogens 3% 6 =0.5%per H two secondary hydrogens48.%per H 2 The 2 hydrogens are 48.5 0.5 =97 times as reactive as the 1 hydrogens. Chapter 4 5Rate of Substitution in the Bromination of Propane Chapter 4 5