89.2 Reaction rate and rate equation (1) Expression of reaction rate △[A] H2+L2=2HI H2+ Cl2=2 HCI △t r=[H2][2]】r=k[H2C12 0.5 [A] t Logical method? ac c dt(1) Expression of reaction rate §9.2 Reaction rate and rate equation 2 1 2 1 [A] = c c r t t t      d[A] r dt  dt d J   dt d c r i i 1 [ ]   H2 + I2 = 2 HI 1 1 2 2 r k  [H ] [I ] H2 + Cl2 = 2 HCl 1 0.5 2 2 r k  [H ] [Cl ] A A B C dc r kc c c dt       Logical method?