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- 1. Multiple-choice3 minutes1 pt
The average rate of disappearance of ozone in the reaction 2O3(g) → 3O2(g) is found to be 8.9 x 10–3 atm over a certain interval of time.
What is the rate of appearance of O2 during this interval?
1.3 x 10–2 atm/time
8.9 x 10–3 atm/time
5.9 x 10–3 atm/time
2.7 x 10–2 atm/time
1.8 x 10–2 atm/time
- 2. Multiple-choice3 minutes1 pt
The rate expression for a particular reaction is Rate = k[A][B]2.
If the initial concentration of B is increased from 0.1 M to 0.3 M, the initial rate will increase by which of the following factors?
3
27
4
6
9
- 3. Multiple-choice3 minutes1 pt
For the reaction: 2HI → 2H2 + I2
If HI is first order, which of the following will yield a linear plot?
log [HI] vs time
1/[HI] vs time
[HI]2 vs time
[HI] vs time
ln[HI] vs time
- 4. Multiple-choice3 minutes1 pt
For the reaction: 2HI → 2H2 + I2
If HI is first order, which of the following will yield a negative exponential plot?
log [HI] vs time
1/[HI] vs time
[HI]2 vs time
[HI] vs time
ln[HI] vs time
- 5. Multiple-choice3 minutes1 pt
For the reaction: 2HI → 2H2 + I2
If HI is second order, which of the following will yield a linear plot?
log [HI] vs time
1/[HI] vs time
[HI]2 vs time
[HI] vs time
ln[HI] vs time
- 6. Multiple-choice3 minutes1 pt
For the reaction: 2HI → 2H2 + I2
If HI is second order, will plotting 1/[HI] vs time give a positive or negative slope?
positive
negative
- 7. Multiple-choice3 minutes1 pt
Which of the following statements is typically true for a catalyst?
The concentration of the catalyst will go down as the reaction proceeds
The catalyst provides a new pathway in the reaction mechanism
The catalyst speeds up the reaction
B and C
All of the above
- 8. Multiple-choice3 minutes1 pt
The catalyzed reaction has a _____ activation energy and thus causes a _____ reaction rate.
higher, lower
higher, higher
higher, steady
lower, higher
lower, steady
- 9. Multiple-choice3 minutes1 pt
Consider the following mechanism:
A2 + B2 → R + C (slow)
A2 + R → C (fast)
Which is the intermediate?
A2
A
B
R
C
- 10. Multiple-choice3 minutes1 pt
Consider the following mechanism:
A2 + B2 → R + C (slow)
A2 + R → C (fast)
What is the overall simplified balanced equation?
A2 + B2 → R + C
A2 + R → C
2A2 + B2 → 2C
2A2 + B2 → C
2A2 + 2B2 → 2C
- 11. Multiple-choice3 minutes1 pt
Consider the following mechanism:
A2 + B2 → R + C (slow)
A2 + R → C (fast)
What is the order with respect to each reactant?
A2: 1; B2: 1
A2: 1; B2: 0
A2: 0; B2: 1
A2: 1; B2: 2
A2: 2; B2: 1
- 12. Multiple-choice3 minutes1 pt
A first-order reaction is 43% complete at the end of 18 min.
What is the value of the rate constant?
3.1 x 10-2 min-1
0.21 min-1
0.071 min-1
4.7 x 10-2 min-1
1.4 x 10-2 min-1
- 13. Multiple-choice3 minutes1 pt
For which order reaction is the half-life of the reaction independent of the initial concentration of the reactant(s)?
zero order
first order
second order
all of these
none of these
- 14. Multiple-choice5 minutes1 pt
The following data were measured for the reaction BF3(g) + NH3(g) —> F3BNH3(g)
What is the rate law for the reaction?
R=k[NH3]
R=k[BF3]2[NH3]
R=k[BF3][NH3]
R=k[BF3][NH3]2
- 15. Multiple-choice3 minutes1 pt
The following data were measured for the reaction BF3(g) + NH3(g) —> F3BNH3(g):
Calculate the rate constant with proper units?
3.408 M2-s-
4.26 s-
3.408 M-s-
4.26 M-s-
- 16. Multiple-choice3 minutes1 pt
Given the rate law: Rate = k[A][B]
What is the unit of k?
s-1
s
L mol-1 s-1
L2 mol-2 s-1
mol L-1 s-1
- 17. Multiple-choice3 minutes1 pt
Given the rate law: Rate = k[B]
What is the unit of k?
s-1
s
L mol-1 s-1
L2 mol-2 s-1
mol L-1 s-1
- 18. Multiple-choice3 minutes1 pt
Given the rate law: Rate = k
What is the unit of k?
s-1
s
L mol-1 s-1
L2 mol-2 s-1
mol L-1 s-1
- 19. Multiple-choice3 minutes1 pt
The decomposition of carbon disulfide, CS2, to carbon monosulfide, CS, and sulfur is first order with k = 2.8 x 10-7 s-1at 1000oC.
CS2 → CS + S
What is the half-life of this reaction at 1000oC?
5.0 x 107 s
4.7 x 10-6 s
3.8 x 105 s
6.1 x 104 s
2.5 x 106 s
- 20. Multiple-choice3 minutes1 pt
Given that a reaction absorbs energy and has an activation energy of 50 kJ/mol, which of the following statements is correct?
The reverse reaction has an activation energy equal to 50 kJ/mol.
The reverse reaction has an activation energy less than 50 kJ/mol.
The reverse reaction has an activation energy greater than 50 kJ/mol.
