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Entry Task: Nov 3rd Monday

Sign off on Rate Law ws

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Agenda:

• Go through the answers to Rate Law ws• HW: Expression and Rate Law ws

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Clear off Desks:Calculator and handout only

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1. For 2 A + B C, we’ve determined the following experimental data:

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

1 2

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

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2. For 2 A + B C, we’ve determined the following experimental data:

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]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

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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] = 0.050 M and [H2] = 0.150 M.

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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

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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 22 . This means that NO is 2nd order [NO]2

a) Rate = k[NO]2[H2]1

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3. Using these data, determine (a) the rate law for the reaction, (b) the rate constant, c) the rate of the reaction when [NO] = 0.050 M and [H2] = 0.150 M. a) Rate = k[NO]2[H2]1

k=Rate

[NO]2[H2]1=

4.92 x 10-3 M/s[0.20M]2[0.10M]1

= 1.2 M-2/s-1

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3. Using these data, determine (a) the rate law for the reaction, (b) the rate constant, (c) the rate of the reaction when [NO] = 0.050 M and [H2] = 0.150 M.

a) Rate = k[NO]2[H2]1

b) k = 1.2 M2 s1

Rate = (1.2 M2 s1) (0.050 M)2(0.150M)

Rate = 4.5 x 10-4 M/s

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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

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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

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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

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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 0

Rate = k [X] 1

6.00 x 10-3 M/s = k [1.00 x10-2 M] 0.600 s-1

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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

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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

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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 0

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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 [0.0500 M] [0.0500 M]2 50 M-2 s-1

0

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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

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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

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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 0.20 242 0.25 0.20 1503 0.10 0.50 604 0.35 0.50 735

0.10 = 24_ 0.25 = 150

NO is 2nd order(0.4)m = 0.16

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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 0.20 242 0.25 0.20 1503 0.10 0.50 604 0.35 0.50 735

(0.10)m = 24_ (0.25)m = 150

NO is 2nd order(0.4)m = 0.16

(0.20)m = 24_ (0.50)m = 60

Br2 is 1st order(0.4)m = 0.4

24 M/s = k [0.10 M]2 [0.20 M]

12000 M-2 s-1

Rate = k [NO]2[Br2]

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.

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

B is 1st order(0.67)m = 0.67

(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]

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.

5. The value of the specific rate constant is:

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

Rate = k[A]2[B][C]

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.

6. The missing rate (trial 5) in units of M/s should be:

? M/s = 1.25 x 106 M-3s-1 [0.05]2[0.01][0.08]

2.5 M/s

Rate = k[A]2[B][C]

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):

Let’s use -1/3 ∆C/∆t = 1/2 ∆Y/∆t

We can compare C disappearing with the rate of Y appearing through stoich!

13

[C]∆t= −1

215 M/s

= 32

15M/s22.5 M

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.

8. Doubling [B] would change the rate of formation Y by a factor of:

C would double as well!

Rate = k[A]2[B][C]

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):

Let’s use -1/3 ∆C/∆t = 1/2 ∆Y/∆t

We can compare Y disappearing with the rate of Z appearing through stoich!

11

[Z]∆t= −1

280 M/s

= 12

80M/s40 M/s

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