Which of the following is incorrect about the order of reaction?

The order of reaction cannot be fractional

The incorrect statement about the order of the reaction is:

(3) The order of reaction cannot be fractional.

In reality, the order of reaction can indeed be fractional. The order of reaction represents the exponent or power to which the concentration of a reactant is raised in the rate law expression. It is determined experimentally by analyzing the rate of the reaction under different concentrations of the reactants.

In certain cases, experimental data may indicate that the reaction rate is not directly proportional to the concentration of a reactant raised to a whole number. Instead, it may exhibit a fractional order, indicating a complex or non-elementary reaction mechanism.

Therefore, the correct statement is that the order of reaction can be fractional, making a statement (3) incorrect.