Question

Assertion: Order of the reaction can be zero or fractional.
Reason: We cannot determine order from the balanced chemical equation.
(A) Both assertion and reason are correct and reason is the correct explanation of assertion
(B) Both assertion and reason are correct and reason does not explain assertion
(C) Assertion is correct but reason is incorrect
(D) Both assertion and reason are incorrect
(E) Assertion is incorrect but reason is correct

Answer 1

Hint: To answer this question, you must recall the properties of the order of a chemical reaction. The order of a chemical reaction is given as the sum of the exponential powers of the concentration of reactant terms in the rate law expression.

Complete step by step solution
If we are given the rate law expression of a reaction, we can determine the order of that reaction by adding the powers of the concentration terms of the reactants. The order of a reaction plays an important role in the properties and propagation of a chemical reaction. A reaction can be first order reaction, second order reaction, third order reaction, pseudo first order reaction, etc.
The order of a reaction is determined experimentally or theoretically only if the experimentally deduced rate law expression for the reaction is given to us. The order of a reaction can be either an integral value or fractional value.
Thus, both the assertion and reason statements are true but the reason does not give an explanation of the assertion.
Thus, the correct answer is B.

Note
The order of a reaction can be equal to zero. In such a reaction, the rate of the reaction is independent of the concentrations of the reactants.
The order can be a negative integral value. In this case, the rate of the reaction is inversely affected by the concentrations of the reactants.
The order can be a positive integral value which indicates that the rate of the reaction is affected directly by the concentration of the reactants.
The order can also be equal to a fractional value. It indicates an intricate relationship between the rate of the reaction and the concentration of the reactants. It is generally possessed by complex reactions.