Applicability of Statements to a Balanced Chemical Equation of an Elementary Reaction


In chemistry, a balanced chemical equation represents a chemical reaction by showing the number of reactant molecules and product molecules involved. An elementary reaction is a reaction that occurs in a single step, involving the collision of reactant molecules and the formation of products. In this context, let us analyze the applicability of the given statements to a balanced chemical equation of an elementary reaction.


The order of a reaction is the sum of the exponents in the rate equation, which represents the dependence of the reaction rate on the concentration of reactants. On the other hand, molecularity refers to the number of molecules or ions that participate in an elementary reaction. For an elementary reaction, the order of the reaction is equal to the molecularity.

Conclusion: Statement (a) is applicable to a balanced chemical equation of an elementary reaction.


As explained above, the order of a reaction is equal to the molecularity for an elementary reaction. Hence, the order cannot be less than the molecularity.

Conclusion: Statement (b) is not applicable to a balanced chemical equation of an elementary reaction.


As mentioned earlier, the order of a reaction is equal to the molecularity for an elementary reaction. Therefore, the order cannot be greater than the molecularity.

Conclusion: Statement (c) is not applicable to a balanced chemical equation of an elementary reaction.


Molecularity represents the number of molecules or ions involved in an elementary reaction. Since an elementary reaction involves the collision of molecules, there must be at least one molecule participating in the reaction. Hence, molecularity can never be zero.

Conclusion: Statement (d) is applicable to a balanced chemical equation of an elementary reaction.


In summary, the applicable statements to a balanced chemical equation of an elementary reaction are:
- Statement (a): Order is same as molecularity.
- Statement (d): Molecularity can never be zero.

Therefore, the order of an elementary reaction is equal to the molecularity, and molecularity cannot be zero.