For a reaction, `I^(-) + OCl^(-) to IO^(-) + Cl^(-)` in an aqueous medium, the rate of reaction is given by `(d[IO^(-)])/(dt) = k ([I^(-)[OCl^(-)])/([OH^(-)]))`. The overall order of reaction is

Options

A. `-1`
B. 0
C. 1
D. 2

Explanation

To determine the overall order of the reaction given by the rate law:

\[ \frac{d[IO^-]}{dt} = k \frac{[I^-][OCl^-]}{[OH^-]} \]

we need to analyze the rate expression step by step.

### Step 1: Identify the concentration terms in the rate law
The rate law provided indicates that the rate of formation of \( IO^- \) is dependent on the concentrations of \( I^- \), \( OCl^- \), and \( OH^- \).

### Step 2: Determine the order with respect to each reactant
- The concentration of \( I^- \) appears in the numerator, indicating that the reaction is first order with respect to \( I^- \).
- The concentration of \( OCl^- \) also appears in the numerator, indicating that the reaction is first order with respect to \( OCl^- \).
- The concentration of \( OH^- \) appears in the denominator, which indicates that the reaction is first order with respect to \( OH^- \) but since it is in the denominator, it effectively contributes a negative order.

### Step 3: Calculate the overall order of the reaction
The overall order of the reaction can be calculated by summing the individual orders:
- Order with respect to \( I^- \): 1
- Order with respect to \( OCl^- \): 1
- Order with respect to \( OH^- \): -1 (since it is in the denominator)

Now, we can sum these contributions:
\[ \text{Overall order} = 1 + 1 - 1 = 1 \]

### Conclusion
The overall order of the reaction is 1.

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