Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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Which statement does not represent a rate?
a. | The speed of a car is 45 km/h. | b. | The half-life of an element is 12.4
h. | c. | A family consumes 4 L of milk every three days. | d. | It takes 15 min to
walk to the store. | e. | A cat eats three cans of wet food per
week. |
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2.
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Which expression does not represent the rate of the following
reaction?
Mg(s) + 2HCl(aq) → MgCl2(aq) +
H2(g)
a. |  | b. |  | c. |  | d. |  | e. | All of these are accurate representations of
the rate of this reaction. |
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3.
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In the following reaction, butane is consumed at the rate of 0.0333 mol/(L •s). Determine the rate at which CO 2 is
produced. C 4H 10(g) +  O 2(g)
→ 4CO 2(g) +
5H 2O (g)a. | 0.008 25 mol/(L•s) | b. | 0.0165 mol/(L•s) | c. | 0.0333 mol/(L•s) | d. | 0.0667 mol/(L•s) | e. | 0.133 mol/(L•s) |
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4.
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Given the following reaction mechanism, what is the equation for the overall
reaction?
2A → B + 2C (slow)
B
+ C → D + E
(fast)
C + D → E + F (fast)
a. | 2A → 2E +
F | b. | 2A + B + 2C → D + 2E +
F | c. | 2A + 2C → 2E + F | d. | 2A + B + 2C + D → B + 2C + D + 2E + F | e. | 2A + C → 2E + F |
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5.
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The isotope  has a half-life of 165 days. The isotope  has a half-life of 330 days. Which statement about these two isotopes is false? a. | One year represents slightly more than two half-lives of a sample of the calcium
isotope. | b. | Almost all of 100 g of the calcium isotope will decay in one year’s
time. | c. | 100 g of the vanadium isotope will decay to somewhat less than 50 g in a
year. | d. | The calcium isotope decays at twice the rate of the vanadium
isotope. | e. | All of these statements are true. |
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Short Answer
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For the following questions, write the most appropriate answer in the space
provided.
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6.
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What is the order of the reaction with the rate law expression r = k[A]0[B]1?
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7.
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Use the collision theory to explain the rate at which gas reactions usually
occur.
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8.
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The reactant concentration of a first-order reaction is 0.05 mol/L, and the rate
constant is 0.25 s−1. What is the rate of this
reaction?
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Problem
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Graphics
For the following questions, use the graphics
provided to review terms or skills. Add any missing labels, draw any missing parts, or use the
graphics to help you answer a question.
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9.
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The following graph represents the concentration of
H 2O 2(aq) over time for the decomposition of hydrogen peroxide into
water. 2H 2O 2(aq) →
2H 2O (l) + O 2(g)
a) What
would you do to determine the rate of reaction at A? b) Compare the rate of reaction at A with the
rate of reaction at B. Explain the difference in terms of the collision theory. c) Sketch the
general shape of the curve, showing the concentration of H 2O versus time on the same
graph.
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10.
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Use a Maxwell-Boltxmann diagram to help you explain why an increase in
temperature results in an increase in the rate of reaction.
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11.
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Consider the following series of potential energy diagrams.  a) Which diagram represents the fastest
reaction at room temperature? Explain your choice. b) Which diagram represents the reaction of two
solids at room temperature? Explain your choice.
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Critical Thinking
For the following questions, write the answer in
the space provided. Use complete sentences in your answer. If the question requires mathematical
calculations, show all of your work. Write a final statement that gives your solution.
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12.
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Doubling the concentration of hydroxide ions in the following reaction causes
the reaction rate to double. Doubling the concentration of both reactants causes the reaction rate to
increase by a factor of four. C 2H 5Br (aq) + OH −(aq) → C 2H 5OH (aq) +
Br −(aq)a)
What is the order of the reaction with respect to hydroxide ions?
b) What is the order of the
reaction with respect to bromoethane?
c) What is the overall reaction order?
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Applications
For the following questions, write the answer in the
space provided. Use complete sentences in your answer. If the question requires mathematical
calculations, show all of your work. Write a final statement that gives your solution.
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13.
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Why are catalysts important in industries? Give one example of an industrial
catalyst.
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