Consider the aqueous reaction:
Overall reaction: 2A(aq) + B(aq) → products
Mechanistic evidence suggests the following two-step pathway at 25 °C:
Step 1 (slow): A(aq) + B(aq) → C(aq)
Step 2 (fast): C(aq) + A(aq) → products
In one experiment the initial concentrations are [A]₀ = 0.10 M and [B]₀ = 0.20 M, producing an initial rate r₀.
(a) Determine the rate law implied by the mechanism.
(b) The chemist repeats the experiment with [A]₀ doubled to 0.20 M while [B]₀ remains 0.20 M. Calculate the factor by which the initial rate changes relative to r₀.
(c) A third trial is conducted with [B]₀ tripled to 0.60 M while [A]₀ stays at 0.10 M. Calculate the numerical factor change in the initial rate relative to r₀.
(d) Explain why the two factors obtained in parts (b) and (c) differ in magnitude.
(a) Determine the rate law predicted by the mechanism.
(b) Calculate the factor by which the initial rate changes when [A]₀ is doubled.
(c) Calculate the factor by which the initial rate changes when [B]₀ is tripled.
(d) Explain the difference between the factors obtained in parts (b) and (c).