For the rate expression rate 3/2 k A B the overall order of a reaction is — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

# Solution: Overall Order of Reaction **Given rate expression:** $$\text{rate} = k[A]^{3/2}[B]^1$$ **Step 1: Identify individual orders** - Order with respect to $[A]$ = $\frac{3}{2}$ - Order with respect to $[B]$ = $1$ **Step 2: Calculate overall order** The overall order is the sum of all individual orders: $$\text{Overall order} = \frac{3}{2} + 1 = \frac{5}{2} = 2.5$$ **Why this is correct:** The overall order of a reaction is defined as the sum of the exponents of all concentration terms in the rate law. Since the exponents are $\frac{3}{2}$ and $1$, their sum gives $\frac{5}{2}$ or **2.5** (order B). **Note:** This is a non-integer order, which is common in complex reactions involving multiple elementary steps, particularly when chain mechanisms or equilibrium pre-equilibria are involved.