1.)Consider the following initial rate data that were collected for the general

Question

1.)Consider the following initial rate data that were collected for the general reaction below to answer the next three questions:

Experiment

[AB2] (M)

[C] (M)

Initial Rate (M/s)

1

0.12

0.23

2.46 x 10-2

2

0.36

0.23

2.21 x 10-1

3

0.36

0.46

2.21 x 10-1

What is the rate law for this reaction?

B.)What is the numerical value of the rate constant, k for this reaction? (Use Experiment 1 to determine this constant.)

C.)   What are the units for the rate constant, k in the reaction above?

Experiment

[AB2] (M)

[C] (M)

Initial Rate (M/s)

1

0.12

0.23

2.46 x 10-2

2

0.36

0.23

2.21 x 10-1

3

0.36

0.46

2.21 x 10-1

Explanation / Answer

1) let the rate law be

rate = K [AB2]^a [C]^b

for exp1 and exp2

we can see that , [C] is constant

so

rate2 / rate1 = ( [AB2]2 / [AB]1 )^a

2.21 x 10-1 / 2.46 x 10-2 = ( 0.36/0.12)^a

9 = ( 3)^a

a = 2

now

for exp2 and exp3 , [AB2] is constant

so

rate3/rate2 = ( [C]3/[C]2 )^b

2.21 x 10-1 / 2.21 x 10-2 = ( 0.46/0.23)^b

1 = (2)^b

b = 0

so

the rate law is given by

rate = k [AB2]^2 [C]^0

rate = k [AB2]^2

2)

now for exp1

2.46 x 10-2 = k [ 0.12]^2

k = 1.7

so

the value of rate constant (k) is 1.7

3)

now

for a reaction with order n ,

the unit of rate constant is M^(1-n) S-1

in this case

order = 2

so

unit of rate constant is M-1 s-1

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.