The reaction A+B⟶C+Drate=𝑘[A][B]2A+B⟶C+Drate=�⁡[A]⁢[B]2 has an initial rate of 0.0920 M/s.0.0920 M/s. What will the initial rate be if [A][A] is halved and [B][B] is tripled?

Question

The reaction

A+B⟶C+Drate=𝑘[A][B]2A+B⟶C+Drate=�⁡[A]⁢[B]2

has an initial rate of 0.0920 M/s.0.0920 M/s.

What will the initial rate be if [A][A] is halved and [B][B] is tripled?

initial rate:

M/sM/s

What will the initial rate be if [A][A] is tripled and [B][B] is halved?

Answer 1

Rate = k[A][B]²

This tells us that the rate is directly proportional to the [A] and to the [B] squared.

(0.5)(3)² = 4.5

So, initial rate should be 4.5 x 0.0920 M/s = 0.414 M/s

If [A] is tripled and [B] is halved...

(3)(0.5)² = 0.75

So, initial rate should be 0.75 x 0.0920 M/s = 0.069 M/s