1. Entry Task: Nov 3rd Monday
Sign off on Rate Law ws
MAYHAN

2. Agenda: Go through the answers to Rate Law ws
HW: Expression and Rate Law ws
MAYHAN

3. Clear off Desks: Calculator and handout only
MAYHAN

4. MAYHAN

5. 1 2 Rate = k[A]1[B]2 3 1.62 x10-5 = k[0.0100M]1[0.0100M]2
1. For 2 A + B  C, we’ve determined the following experimental data: 1 2
a. Rate order for A is _____and B is______
b. The rate law for this reaction is:
c. The overall reaction order is_______.
d. Provide the rate constant for this reaction
Rate = k[A]1[B]2 3
1.62 x10-5 = k[0.0100M]1[0.0100M]2
1.62 x10-5 M/s = k= 16.2 M-2s-1
1.0 x10-6 M3
MAYHAN

6. 2 1 Rate = k[A]2[B]1 3 2.80 x10-3 M/s = k[0.026 M]2[0.015 M]1
2. For 2 A + B  C, we’ve determined the following experimental data: 2 1
a. Rate order for A is _____and B is______
b. The rate law for this reaction is:
c. The overall reaction order is_______.
d. Provide the rate constant for this reaction
Rate = k[A]2[B]1 3
2.80 x10-3 M/s = k[0.026 M]2[0.015 M]1
2.80 x10-3 M/s= k= 277 M-2s-1
1.01 x10-5 M3
MAYHAN

7. 3. The following data were measured for the reaction of nitric oxide with hydrogen: 2 NO(g) + 2 H2(g)  N2(g) + 2 H2O(g)
Using these data, determine (a) the rate law for the reaction, (b) the rate constant, (c) the rate of the reaction when [NO] = M and [H2] = M.
MAYHAN

8. 3. Using these data, determine (a) the rate law for the reaction
Exp. 1 vs. Exp. 2, we doubled the concentration of H2, the rate doubled as well. This means [H2]1
MAYHAN

9. 3. Using these data, determine (a) the rate law for the reaction
Exp. 1 vs. Exp. 2, we doubled the concentration of H2, the rate doubled as well. This means [H2]1
Exp. 2 vs. Exp. 3, we doubled the concentration of NO and the rate quadrupled or This means that NO is 2nd order [NO]2
a) Rate = k[NO]2[H2]1
MAYHAN

10. a) Rate = k[NO]2[H2]1 Rate 4.92 x 10-3 M/s k= = = 1.2 M-2/s-1
3. Using these data, determine (a) the rate law for the reaction, (b) the rate constant, c) the rate of the reaction when [NO] = M and [H2] = M.
a) Rate = k[NO]2[H2]1
Rate
4.92 x 10-3 M/s k= =
= 1.2 M-2/s-1
[NO]2[H2]1
[0.20M]2[0.10M]1
MAYHAN

11. 3. Using these data, determine (a) the rate law for the reaction, (b) the rate constant, (c) the rate of the reaction when [NO] = M and [H2] = M.
a) Rate = k[NO]2[H2]1
b) k = 1.2 M2 s1
Rate = (1.2 M2 s1) (0.050 M)2(0.150M)
Rate = 4.5 x 10-4 M/s
MAYHAN

12. 2 4. Using this information,
a. Rate order for A is _____and B is______
b. The rate law for this reaction is:
 c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 2
MAYHAN

13. 2 1 Rate = k [A]2[B] 3 1.04 M-2s-1 4. Using this information,
a. Rate order for A is _____and B is______
b. The rate law for this reaction is:
 c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 2 1
Rate = k [A]2[B] 3
0.26 x 10-9 M/s = k
[1.00 x10-3M]2[0.25 x10-3M]
1.04 M-2s-1
MAYHAN

14. 1 5. Using this information,
a. Rate order for X is _____and Y is______
b. The rate law for this reaction is:
 c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 1
MAYHAN

15. 1 Rate = k [X] 1 0.600 s-1 5. Using this information,
a. Rate order for X is _____and Y is______
b. The rate law for this reaction is:
 c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 1
Rate = k [X] 1
6.00 x 10-3 M/s = k
[1.00 x10-2 M]
0.600 s-1
MAYHAN

16. 1 6. Using this information,
a. Rate order for A is _____, B is______ , and C is_____
b. The rate law for this reaction is:
 c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 1
MAYHAN

17. 2 1 6. Using this information,
a. Rate order for A is _____, B is______ , and C is_____
b. The rate law for this reaction is:
 c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 1 2
MAYHAN

18. 2 1 6. Using this information,
a. Rate order for A is _____, B is______ , and C is_____
b. The rate law for this reaction is:
 c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 1 2
MAYHAN

19. 2 1 Rate = k [A] [B]2 3 50 M-2 s-1 6. Using this information,
a. Rate order for A is _____, B is______ , and C is_____
b. The rate law for this reaction is:
c. The overall reaction order is_______.
d. Provide the rate constant for this reaction 1 2
Rate = k [A] [B]2 3
6.25 x 10-3 M/s = k
[ M] [ M]2
50 M-2 s-1
MAYHAN

20. MAYHAN

21. Calculate Rate constant: Rate = k [A]2 [B]1
1. Using this data:
Rate Law:
Calculate Rate constant:
Rate = k [A]2 [B]1
0.26 x 10-9 M/s = k
[1.00 x 10-3 M]2 [0.25 x10-3M]
1.04 M-2 s-1
MAYHAN

22. Calculate Rate constant: Rate = k [X]1
2. Using this data:
Rate Law:
Calculate Rate constant:
Rate = k [X]1
6.00 x 10-3 M/s = k
[1.00 x 10-2 M]
0.6 s-1
MAYHAN

23. 3. Consider the gas-phase reaction between nitric acid oxide ad bromine at 273°C:
2NO (g) + Br2 (g)  2NOBr (g)
a) Determine the rate law? **Hint get ratios between concentrations and rates.
b) Calculate the average value of the rate constant for the appearance of NOBr from our four data sets.
Trial
[NO] (M)
[Br2] (M)
Initial Rate M/s 1
0.10
0.20 24 2
0.25
150 3
0.50 60 4
0.35
735
= 24_ =
(0.4)m = 0.16
NO is 2nd order
MAYHAN

24. Rate = k [NO]2[Br2] 12000 M-2 s-1 NO is 2nd order Br2 is 1st order
3. Consider the gas-phase reaction between nitric acid oxide ad bromine at 273°C:
2NO (g) + Br2 (g)  2NOBr (g)
a) Determine the rate law? **Hint get ratios between concentrations and rates.
b) Calculate the average value of the rate constant for the appearance of NOBr from our four data sets.
Trial
[NO] (M)
[Br2] (M)
Initial Rate M/s 1
0.10
0.20 24 2
0.25
150 3
0.50 60 4
0.35
735
(0.10)m = 24_
(0.25)m =
(0.20)m = 24_
(0.50)m = 60
(0.4)m = 0.16
NO is 2nd order
Br2 is 1st order
(0.4)m = 0.4
Rate = k [NO]2[Br2]
12000 M-2 s-1
24 M/s = k
[0.10 M]2 [0.20 M]
MAYHAN

25. A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
The following data are for Questions and refer to the reaction:
A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
The rate law derived for the reaction from the above data is:
[A] and [B] kept constant its obvious that [C] is 1st order
(0.02)m = 10_
(0.03)m = 15
(0.67)m = 0.67
B is 1st order
(0.10)m = 10_
(0.20)m = 80
(0.5)m = 0.125
This is 3rd order but we need to subtract 1 for the [C] making A an 2nd order
Rate = k[A]2[B][C]

26. A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
The following data are for Questions and refer to the reaction:
A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
5. The value of the specific rate constant is:
Rate = k[A]2[B][C]
10 M/s = k [0.10]2[0.02][0.04]
__ 10 M/s_ __ = k [0.10]2[0.02][0.04]
= 1.25 x 106 M-3s-1

27. A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
The following data are for Questions and refer to the reaction:
A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
6. The missing rate (trial 5) in units of M/s should be:
Rate = k[A]2[B][C]
? M/s = 1.25 x 106 M-3s-1 [0.05]2[0.01][0.08]
2.5 M/s

28. The following data are for Questions 4 - 9 and refer to the reaction:
A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
7. The rate of disappearance of C in trial 2 was (in M/s):
We can compare C disappearing with the rate of Y appearing through stoich!
Let’s use -1/3 ∆C/∆t = 1/2 ∆Y/∆t 1 3 1 2
[C] ∆t
15 M/s
= − 3 2
22.5 M =
15M/s

29. A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
The following data are for Questions and refer to the reaction:
A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
8. Doubling [B] would change the rate of formation Y by a factor of:
Rate = k[A]2[B][C]
C would double as well!

30. The following data are for Questions 4 - 9 and refer to the reaction:
A + 2B + 3C → 2Y + Z. All data were taken at 50.0°C.
9. The rate of formation of Z in trial 3 was (in M/s):
We can compare Y disappearing with the rate of Z appearing through stoich!
Let’s use -1/3 ∆C/∆t = 1/2 ∆Y/∆t 1 1 2
[Z] ∆t
80 M/s
= − 1 2
40 M/s =
80M/s

31. MAYHAN