Question

For the following reaction, state the order with respect to the reactant and the overall order.

\[\ce{H2O2 + 3I- + 2H+ -> 2H2O + I_3^-}\] Rate = k[H₂O₂][I⁻]

Answer 1

For the reaction

\[\ce{H2O2 + 3I- + 2H+ -> 2H2O + I_3^-}\]

The given rate law is 

Rate = k[H₂O₂][I⁻]

Order with respect to each reactant:

[H₂O₂] appears to the power of 1 → Order with respect to H₂O₂ = 1

[I⁻] appears to the power of 1 → Order with respect to I⁻ = 1

[H⁺] does not appear in the rate law → Order with respect to H⁺ = 0

Overall order = 1(H₂O₂) + 1(I⁻) = 2