You and your lab partner are studying the rate of a reaction, A + B --> C. You m
ID: 886691 • Letter: Y
Question
You and your lab partner are studying the rate of a reaction, A + B --> C. You make measurements of the initial rate under the following conditions:
(a) Which of the following reactant concentrations could you use for experiment 3 in order to determine the rate law, assuming that the rate law is of the form, Rate = k [A]x [B]y? Choose all correct possibilities.
[A] = 0.8 and [B] = 1.7
[A] = 0.2 and [B] = 3.4
[A] = 0.4 and [B] = 3.4
[A] = 1.0 and [B] = 1.7
[A] = 0.6 and [B] = 1.7
[A] = 0.4 and [B] = 1.7
[A] = 0.4 and [B] = 5.1
[A] = 0.2 and [B] = 5.1
(b) For a reaction of the form, A + B + C --> Products, the following observations are made: doubling the concentration of A increases the rate by a factor of 4, doubling the concentration of B has no effect on the rate, and doubling the concentration of C increases the rate by a factor of 2. Select the correct rate law for this reaction from the choices below.
Rate = k[A][B][C]
Rate = k[A][C]
Rate = k[A]2 [C]
Rate = k[A][C]2
Rate = k[A]2 [C]2
Rate = k[A]3 [C]
Rate = k[A][C]3
(c) By what factor will the rate of the reaction described in part (b) above change if the concentrations of A, B, and C are all halved (reduced by a factor of 2)?
The rate will be the original rate multiplied by a factor of ----------- .
Explanation / Answer
a)
This question doesn't make sense.At the end of the day you need to calculate x and y.It can be calculated from any of the values.
But for easy calcultion you can chose:
[A] = 0.2 and [B] = 3.4
[A] = 0.4 and [B] = 3.4
[A] = 0.6 and [B] = 1.7
[A] = 0.4 and [B] = 1.7
[A] = 0.4 and [B] = 5.1
[A] = 0.2 and [B] = 5.1
b)
doubling the concentration of A increases the rate by a factor of 4 : so power of A is 2
doubling the concentration of B has no effect on the rate: so power of B is 0
doubling the concentration of C increases the rate by a factor of 2 : so power of C is 1
Answer:
Rate = k[A]2 [C]
c)
If A is halved : reaction will multipled by 1/4
If B is halved : reaction will have no effect : multiplied by 1
If C is halved : reaction will multipled by 1/2
So, rate will be multiplies by (1/4)*1*(1/2) = 1/8
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.