Question

(ii) Account for the following:
(I) We cannot determine the order of a reaction by taking into consideration the balanced chemical equation.
(II) A bimolecular reaction may become kinetically first order under a specified condition.

Hint:

The reaction order must be determined experimentally, as it depends on the mechanism and concentration dependencies, not just the balanced equation.

Answer 1

(I) The balanced chemical equation does not provide any direct information about the reaction order. The order of a reaction is determined experimentally by observing how the rate changes with respect to the concentration of reactants.
(II) A bimolecular reaction may become first order under certain conditions, such as in the presence of a large excess of one reactant, which makes the concentration of that reactant effectively constant. This can make the reaction appear to be first order with respect to the other reactant.