It is, therefore, evident that complex reactions involving more than
three molecules in the stoichiometric equation must take place in more
than one step KClO3 + 6FeSO4 + 3H2SO4 ® KCl + 3Fe2(SO4)3 + 3H2O
This reaction which apparently seems to be of tenth order is actually
a second order reaction This shows that this reaction takes place in
several steps Which step controls the rate of the overall reaction