22 例：H2+Br2 →2HBr ①Br2+M→2Br+M Ti-k]CBr2 CM ②Br.+H2→HBr+H r2-k2CBr.CH2 ③H+Br2→HB+Br: T3=k3Cu.CBt2 ④H+HBr→H2+Br: T4-kaCa.CHBr ⑤ 2Br+M→BI2+M Ts-ks CBr.CM 总反应速率： r= 1+k HBr Br2