Which of the following statements is not correct about an order of a reaction.
(i) The order of a reaction can be a fractional number.
(ii) Order of a reaction is experimentally determined quantity.
(iii) The order of a reaction is always equal to the sum of the stoichiometric coefficients of reactants in the balanced chemical equation for a reaction.
(iv) The order of a reaction is the sum of the powers of the molar concentration of the reactants in the rate law expression.
The answer is the option (iii). The summation of powers of the reactant’s concentration is used for determining the order of reaction. The order of a reaction is always equal to the sum of the stoichiometric coefficients of reacting species in the balanced chemical equation.