Match the items given in List-I with items given in List-II List-I Li…

The correct answer is Option (1) → (A)-(II), (B)-(III), (C)-(IV), (D)-(I)

For a reaction \( \mathrm{A} + \mathrm{B} \rightarrow \text{products} \), the dependence of rate on concentration is written as a rate law, \( \text{Rate} = k[\mathrm{A}]^{x}[\mathrm{B}]^{y} \), where k is the rate constant and x + y is the order. Each item below follows from this one expression.

• (A) Mathematical expression for the rate of reaction is — This matches (II) rate law. The rate law (rate equation) gives the rate in terms of the molar concentrations of the reactants, each raised to a power found by experiment.

• (B) The rate of reaction for zero order reaction is equal to — This matches (III) rate constant. For a zero order reaction the concentration term is raised to the power zero, and any quantity to the power zero is 1:

      \( \displaystyle \text{Rate} = k[\mathrm{A}]^{0} = k \)

• (C) The unit of rate constant for zero order reaction is the same as that of — This matches (IV) rate of a reaction. Since Rate = k for zero order, both have the same unit:

      \( \displaystyle k = \frac{\text{Rate}}{[\mathrm{A}]^{0}} = \text{Rate} \Rightarrow \text{unit of } k = \mathrm{mol\,L^{-1}\,s^{-1}} \)

• (D) The rate of a complex reaction is determined by — This matches (I) rate of slowest step. A complex reaction takes place in several elementary steps, and the rate of the whole reaction cannot be faster than its slowest step, called the rate determining step.

Shortcut: (A)-(II) appears only in Options (1) and (2), and (C)-(IV) then leaves only Option (1).