Assertion (A): The order of a reaction can have fractional value. Reason (R): The order of a reaction cannot be written from balanced equation of a reaction.

The order of a reaction can have fractional value. Assertion is true. The order of a reaction can not be written from balanced equation of a reaction because its value changes with pressure, temperature and concentration. It can only be determined experimentally. Thus the reason is also correct, but the reason is not the correct explanation of assertion.