In the reaction 3 BrO⁻(aq) → BrO₃⁻(aq) + 2 Br⁻(aq), a plot of 1/[BrO⁻] vs. time is linear. What does this indicate about the order of the reaction with respect to BrO⁻?

• A. Second order
• B. Third order
• C. Zero order
• D. First order

Answer: (A)

Verified step by step guidance

1. Understand that the plot of 1/[BrO⁻] vs. time being linear indicates a specific relationship between concentration and time for the reaction.
2. Recall that for a second-order reaction, the integrated rate law is given by: $\frac{1}{C}=\mathrm{kt}+\frac{1}{C}$, where C is the concentration, k is the rate constant, t is time, and C₀ is the initial concentration.
3. Recognize that the linear relationship between 1/[BrO⁻] and time matches the form of the second-order integrated rate law, confirming the reaction order.
4. Consider that for zero-order reactions, the plot of concentration vs. time is linear, and for first-order reactions, the plot of ln(concentration) vs. time is linear.
5. Conclude that the linear plot of 1/[BrO⁻] vs. time indicates the reaction is second order with respect to BrO⁻.