A reaction is first order in A and second order in B. (i) Write the differential rate equation. (ii) How is the rate affected on increasing the concentration of B three times? (iii) How is the rate affected when the concentrations of both A and B are doubled?
Rate = k[A][B]²
The rate becomes 9 times the original rate.
The rate becomes 8 times the original rate.
Explanation
This question tests understanding of rate law expressions and how concentration changes affect reaction rates. For part (i), since the reaction is first order in A and second order in B, the rate equation follows the form Rate = k[A]ˣ[B]ʸ where x=1 and y=2. For part (ii), when B is tripled: Rate' = kA² = 9k[A][B]² = 9×Rate. For part (iii), when both are doubled: Rate' = k(2A)(2B)² = ×k[A][B]² = 8×Rate.