The reaction has an initial rate of 0.0530 M/s. What will the initial rate be if [A] is halved and [B] is tripled?
Answer:
Solution
Given data
Reaction equation
A+ B ----> C+D
Rate = k[A][B]2
Initial rate = 0.0530 M/s
What will the initial rate be if [A] is halved and [B] is tripled
What will the initial rate be if [A] is tripled and [B ] is halved
Lets first calculate the rate constant for the reaction
Assume concentration of the [A] and [B] = 1
Now lets use these concentration to calculate the initial rate constant
Rate = k[A][B]2
0.0530 M/s = k [ 1] [1]2
K = 0.0530 M/s / 1
K= 0.0530 M/s
Now lets use this rate constant and calculate the initial rates when the [A] is halved and [B] is tripled
So new concentration of [A] = 1 /2 = 0.5 M
And [B] = 1 * 3 = 3 M
Rate = k[A][B]2
Rate = 0.0530 M/s * [0.5] [3]2
Rate = 0.238 M/s
Now lets calculate rate when [A] is tripled and [B] is halved
Then concentration of the [A] = 3 m and [B] = 0.5 M
Lets use these concentrations and calculate the rate
Rate = k[A][B]2
Rate = 0.0530 M/s*[3][0.5]2
Rate = 0.0398 M/s