To determine the overall order of the reaction given the rate equation \(\frac{-Δx}{Δt} = K[X]^2[Y]\), we need to analyze the components of the rate equation step by step. ### Step 1: Understanding the Rate Equation The rate equation describes how the rate of a chemical reaction depends on the concentration of the reactants. In this case, the rate of the reaction is given by: \[ \frac{-Δx}{Δt} = K[X]^2[Y] \] Where: - \(K\) is the rate constant. - \([X]\) is the concentration of reactant X. - \([Y]\) is the concentration of reactant Y. ### Step 2: Identifying the Order with Respect to Each Reactant The order of a reaction with respect to a particular reactant is determined by the exponent of that reactant's concentration in the rate equation. - For reactant \(X\), the exponent is 2. This means the reaction is second order with respect to \(X\). - For reactant \(Y\), the exponent is 1. This means the reaction is first order with respect to \(Y\). ### Step 3: Calculating the Overall Order of the Reaction The overall order of the reaction is the sum of the orders with respect to each reactant. Therefore, we can calculate the overall order as follows: \[ \text{Overall Order} = \text{Order with respect to } X + \text{Order with respect to } Y \] \[ \text{Overall Order} = 2 + 1 = 3 \] ### Conclusion: Correct Answer The overall order of the reaction is **3.0**. Therefore, the correct option is **C. 3.0**. ### Step 4: Analyzing the Other Options - **A. 0.0**: This option suggests that the reaction does not depend on the concentration of the reactants, which is incorrect because the rate equation clearly shows dependence on both \([X]\) and \([Y]\). - **B. 1.0**: This option implies that the reaction is first order overall, which is also incorrect. The sum of the orders (2 + 1) gives 3, not 1. - **C. 2.0**: This option only considers the order with respect to \(X\) and ignores the contribution from \(Y\). The overall order must account for both reactants. - **D. 3.09**: This option is not a valid order of reaction since orders are typically whole numbers or simple fractions. The calculated overall order is exactly 3.0. ### Revision Summary - The overall order of a reaction is the sum of the orders with respect to each reactant. - In the given rate equation, the order with respect to \(X\) is 2 and with respect to \(Y\) is 1. - Therefore, the overall order is \(2 + 1 = 3\). - The correct answer is **C. 3.0**.