The order of the reaction is equal to the sum of the exponents on the right hand side of the rate law. For equation (1) above, the order would be equal to x + y + z. The term order is also applied to specific reactants. Again, using reaction 1 above, reactant 1 would be x order, reactant 2 y order and reactant 3 z order. A reaction that does not depend on the concentrations of the reactants is of zero order and proceeds at a constant rate. A reactant that slows down the rate with an increase in concentration has a negative order.
