Br2 (g)+2NO (g) ? 2 NOBr (g) Step 1: NO (g) + Br2 (g) <-> NOBr2 (g) ( fast reversible) Step 2: NOBr2 (g)+NO (g) ? 2NOBr (sl The experiment all you observed rate law is rate =k [NO]^2 [Br2]. Show this mechanism is valid by deriving the rate law expression and showing that it is equal to the experimentally observed rate law