Match the items of Column I and Column II.
| Column I | Column II | ||
|---|---|---|---|
| A. | Mathematical expression for rate of reaction | 1. | Rate constant |
| B. | Rate of reaction for zero order reaction is equal to | 2. | Rate law |
| C. | Units of rate constant for zero order reaction is same as that of | 3. | Order of slowest step |
| D. | Order of a complex reaction is determined by | 4. | Rate of reaction |
$\mathrm{A.\rightarrow (2)}$ $\quad \mathrm{B} \rightarrow(1) \quad \mathrm{C} \rightarrow(4) \quad \mathrm{D} \rightarrow(3)$
1. Mathematical expression for rate of reaction is known as rate law.
2. Rate of reaction for zero order reaction is equal to rate constant
$$\begin{aligned} & r=k[A]^0 \\ \therefore\quad& r=k \end{aligned}$$
3. Unit of rate of reaction is same as that of rate of reaction.
4. Order of complex reaction is determined by rate of a reaction, which is slowest.
Assertion (A) Order of the reaction can be zero or fractional.
Reason (R) We cannot determine order from balanced chemical equation.
Assertion (A) Order and molecularity are same.
Reason (R) Order is determined experimentally and molecularity is the sum of the stoichiometric coefficient of rate determining elementary step.
Assertion (A) The enthalpy of reaction remains constant in the presence of a catalyst.
Reason (R) A catalyst participating in the reaction forms different activated complex and lowers down the activation energy but the difference in energy of reactant and product remains the same.
Assertion (A) All collision of reactant molecules lead to product formation.
Reason (R) Only those collisions in which molecules have correct orientation and sufficient kinetic energy lead to compound formation.