Question

The rate law for the reaction

A + B + C => D is:

Rate = k[A]2[B]

a. How will the reaction rate change if [A] is doubled?

b. How will the reaction rate change if [B] is decreased to 1/4th of the initial concentration?

c. How will the reaction rate change if [C] is increased by 3times? What is the expected rate constant value for this experiment?

Answer 1

rat is 2nd order with respect of A (a = 2) and 1st order with respect of B (b=1)

then

a)

if [A] is doubled, then (2A)^2 = 4; the rate increases by 4x factor

b)

if [B] is decreased to 1/4, then (1/4)^1 = 1/4 will be de decreased factor, i.e. 4 times slower

c)

If [C] is increased, it will have NO effet in the rate, since it is not dependant

the expected rate value will be

d)

rate = k*(4)(1/4)(1) = K rate; none, there is cancellation of terms (i.e 4x then 1/4 and 1)