For the reaction , the initial rate data is: Exp 1: . Exp 2: . Exp 3: . What is the overall order of — Chemical Kinetics Chemistry Question
Question
For the reaction $A + B \rightarrow \text{Products}$, the initial rate data is: Exp 1: $[A] = 0.015 \text{ M}, [B] = 0.15 \text{ M}, \text{Rate} = 1.8 \times 10^{-3} \text{ M min}^{-1}$. Exp 2: $[A] = 0.090 \text{ M}, [B] = 0.15 \text{ M}, \text{Rate} = 1.08 \times 10^{-2} \text{ M min}^{-1}$. Exp 3: $[A] = 0.015 \text{ M}, [B] = 0.45 \text{ M}, \text{Rate} = 5.4 \times 10^{-3} \text{ M min}^{-1}$. What is the overall order of the reaction?
💡 Solution & Explanation
Let $\text{Rate} = k[A]^x[B]^y$. Dividing Exp 2 by Exp 1: $\frac{1.08 \times 10^{-2}}{1.8 \times 10^{-3}} = \left(\frac{0.090}{0.015}\right)^x \Rightarrow 6 = 6^x \Rightarrow x = 1$. Dividing Exp 3 by Exp 1: $\frac{5.4 \times 10^{-3}}{1.8 \times 10^{-3}} = \left(\frac{0.45}{0.15}\right)^y \Rightarrow 3 = 3^y \Rightarrow y = 1$. The overall order is $x + y = 1 + 1 = 2$.