Answer:
I believe the question is incomplete as the rate equation was not included in the question, but no need to be worried I can be of help. Here is the complete question:
Given: A + 3B 2C + D
This reaction is first order with respect to reactant A and second order with respect to reactant B. If the concentration of A is doubled and the concentration of B is halved, the rate of the reaction would _____ by a factor of _____.
(a) increase, 2
(b) decrease, 2
(c) increase, 4
(d) decrease, 4
(e) not change
Explanation:
Solving the above question, the rate of the reaction will decrease and by factor of 2. How?
K1 = [A] [B]^2 i.e, reactant A is first order, reactant B is second order.
k2 = 2[A] [B/2]^2 that is, concentration of reactant A is doubled, concentration of reactant B is halved.
Comparing both rate of reactions:
k1/k2 = [A] [B/2] / 2[A] [B/2]^2
k1/k2 = 4 [A] [B]^2 /2 [A] [B]^2
k1 /k2 = 4 [B]^2 / 2[B]^2
k1/k2 = 2
The rate of the reaction is therefore decreased and by 2.
With this ideas of how to solve this kind of question, you can use it to solve for the actual question if the question is solved is not the actual one.
