1 / 17

Ken Rogers Miami Killian High

Rate of Reaction. Ken Rogers Miami Killian High. 1. The following data were obtained for a first order rxn. A a B + C. time (seconds) [A] (molarity).

duaneadams
Download Presentation

Ken Rogers Miami Killian High

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Rate of Reaction Ken Rogers Miami Killian High

  2. 1. The following data were obtained for a first order rxn A a B + C time (seconds) [A] (molarity) 0 0.100 100 0.067 200 0.045 300 0.030 400 0.020 500 0.014 Make a graph and calculate the rate (slope) at time 100 s and 300 s.

  3. .10- .095M - .046M .09- D[A] Slope = ----------- = ------------------ .08- Dtime 0 - 200 s .07- = -2.45 x 10-4 M/s .06- .05- [A] .04- D[A] .03- .02- Dt D[A]/Dt = 1.1 x 10-4 M/s .01- 0 100 200 300 400 time (sec)

  4. Time (seconds)[A] (molarity) 0 0.100 100 0.067 200 0.045 300 0.030 400 0.020 500 0.014 Rate 2.45 x 10-4 M/s 0.067 2.45 x 10-4 M/s 1.1 x 10-4 M/s Rate = k [A]1 Rate = k [A]1 2.45 x 10-4 M/s = k [0.067M] 1.1 x 10-4 M/s = k [0.030M] 3.66 x 10-3/s = k 3.66 x 10-3/s = k

  5. Question 2 (a) What is the rate law expression for this reaction? 2 A + B a 3 C experiment initial initial initial rate number [A] [B] of B 1 0.10 0.10 4.0 x 10-4 M/min 2 0.10 0.30 4.0 x 10-4 M/min 2 0.30 0.30 1.2 x 10-3 M/min 2 0.20 0.40 8.0 x 10-4 M/min rate = k [A]x [B]y Solving for x and y means figuring out the order of each reactant.

  6. 2. 2 A + B a 3 C experiment initial initial initial rate number [A] [B] of B not changing 1 0.10 0.10 4.0 x 10-4 M/min 2 0.10 0.30 4.0 x 10-4 M/min 3 0.30 0.30 1.2 x 10-3 M/min 4 0.20 0.40 8.0 x 10-4 M/min 1 0.10 0.10 4.0 x 10-4 M/min 2 0.10 0.30 4.0 x 10-4 M/min x3 (3) x= 1 0 B is zero order

  7. 2. (a) 2 A + B a 3 C experiment initial initial initial rate number [A] [B] of B not changing 1 0.10 0.10 4.0 x 10-4 M/min 2 0.10 0.30 4.0 x 10-4 M/min 3 0.30 0.30 1.2 x 10-3 M/min 4 0.20 0.40 8.0 x 10-4 M/min 2 0.10 0.30 4.0 x 10-4 M/min 3 0.30 0.30 1.2 x 10-3 M/min x3 3 x = 3 1 A is first order

  8. rate = k [A]x [B]y 1 0 B is zero order, A is first order or just rate = k[A]

  9. 2. (b) value of rate constant? k = ? rate = k[A] Pick any experiment and substitute the info... experiment initial initial initial rate number [A] [B] of B 1 0.10 0.10 4.0 x 10-4 M/min rate = k[A] 4.0 x 10- 4 M/min = k [0.10 M]1 k = 4.0 x 10- 3/min or 4.0 x 10- 3 min-1

  10. 2. c) In experiment #1, what is the initial rate of appearance of product C? 2 A + Ba 3 C experiment initial initial initial rate number [A] [B] of B 1 0.10 0.10 4.0 x 10- 4 M/min 2 A + B a 3 C x 3 4.0 x 10- 4 M/min x 3 = 1.2 x 10- 3 M/min rate of B disappearing rate of C appearing

  11. 3. (a) A + B a C experiment initial initial initial rate number [A] [B] of B 1 0.10 0.10 6.0 x 10-3 M/s 2 0.20 0.20 4.8 x 10-2 M/s 3 0.10 0.20 1.2 x 10-2 M/s not changing x2 (2) x = 2 1 B is first order

  12. 3. (a) A + B a C experiment initial initial initial rate number [A] [B] of B not changing 1 0.10 0.10 6.0 x 10-3 M/s 2 0.20 0.20 4.8 x 10-2 M/s 3 0.10 0.20 1.2 x 10-2 M/s (2) x= 4 2 A is second order

  13. A is second order, B is first order….. rate = k [A]2 [B]1

  14. A + B a C experiment initial initial initial rate number [A] [B] of B 1 0.10 0.10 6.0 x 10-3 M/s 2 0.20 0.20 4.8 x 10-2 M/s 3 0.10 0.20 1.2 x 10-2 M/s 3. (b) value of rate constant? k = ? rate = k [A]2 [B]1 6.0 x 10-3 M/s = k [0.10M]2 [0.10M]1 6/M2.s or 6 M-2.s-1

  15. 3. c) What is the overall order for the reaction? 2 + 1 = 3 rate = k [A]2 [B]1 The reaction is 3rd order overall

  16. The End

  17. The End

More Related