5 Written questions
5 Matching questions
- Which is not an example of the effect of subdivision of the reactant on the rate of chemical reaction?
a. Violent explosions that occur in grain elevators.
b. A container of flammable liquid will burn on the surface but allowed to vaporize will burn explosively.
c. A chunk of iron takes months to rust completely while iron wool will rust in days.
d. Some metals may be fused (welded) with minimal loss while their powders will burn in a flame.
e. The Grand Canyon was created by dissolution by water over millions of years.
- Consider the following proposed mechanism. If this mechanism for the overall reaction were correct, and if k1 were much less than k2, then the observed rate law would be
2A C + I
I + B C + D
a. rate = k1[A]
b. rate = k2[I][B]
c. rate = k1[A]2
d. rate = k1[A]2 − k2[C][D]
e. rate = k1k2[A]2[I][B]
- Consider the following first order reaction.
A2B → AB + A
If it takes 87 seconds for the concentration of A2B to be reduced from 2.2 M to 0.12 M, what is the value of the specific rate constant?
a. 0.0334 min−1
b. 2.01 min−1
c. 2.01 s−1
d. 18.3 min−1
e. 3.51 × 10−3 s−1
- Which of the following reactions would be expected to be the slowest?
a. Ag+(aq) + Cl−(aq) → AgCl(s)
b. H+(aq) + OH−(aq) → H2O
c. CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
d. Pb2+(aq) + CrO42−(aq) → PbCrO4(s)
e. H+(aq) + CN−(aq) → HCN(aq)
- For a certain third-order reaction with the general form aA → products, the rate is 0.36 M·s−1 when the concentration of the reactant is 0.35 mol/L. What is the rate constant for this reaction?
a. 0.042 M−2⋅s−1
b. 8.4 M−2⋅s−1
c. 0.36 M−2⋅s−1
d. 0.34 M−2⋅s−1
e. 24 M−2⋅s−1
- a c. CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
- b e. The Grand Canyon was created by dissolution by water over millions of years.
- c c. rate = k1[A]2
- d b. 8.4 M−2⋅s−1
- e b. 2.01 min−1
5 Multiple choice questions
- b. All reactant collisions result in product formation.
- a. 1.87 × 104 s−1
- a. decrease by 3/4
- a. 0.0016 mol/L
- e. The larger its value, the slower the reaction rate.
5 True/False questions
At a certain temperature the reaction below obeys the rate-law expression rate = (1.14 × 10−3 M−1•s−1)[B]2. If 5.00 mol of B is initially present in a 1.00-L container at that temperature, how long would it take for 2.00 mol of B to be consumed at constant temperature?
2B → C + D
a. 224 s
b. 87.5 s
c. 46.0 s
d. 73.0 s
e. 58.5 s → a. 3.10 hrs
Which of the following statements concerning graphical methods for determining reaction order is false?
a. For a first-order reaction the plot of ln[A] vs. time gives a straight line.
b. For a first-order reaction the slope of the straight-line graph equals −ak.
c. For a second-order reaction the plot of [A]2 vs. time gives a straight line.
d. For a first-order reaction the intercept of the straight-line graph equals ln [A]0.
e. For a zero-order reaction the plot of [A] vs. time gives a straight line. → c. For a second-order reaction the plot of [A]2 vs. time gives a straight line.
Which of the following statements about reaction orders in the rate law expression is incorrect?
a. Their values may equal the stoichiometric coefficients in the balanced equation.
b. Their values may or may not equal the stoichiometric coefficients in the balanced equation.
c. Their values must be experimentally determined.
d. Their values get larger as the temperature is increased.
e. An order equal to zero means there is no concentration dependence with rate. → e. The larger its value, the slower the reaction rate.
The catalytic converters installed in newer models of automobiles are designed to catalyze certain kinds of favorable reactions. Unfortunately, other unfavorable reactions also are catalyzed. Which one of those listed below, all of which are catalyzed in such mufflers, is an unfavorable reaction?
a. 2CO(g) + O2(g) → 2CO2(g)
b. 2C8H18(g) + 25O2(g) → 16CO2(g) + 18H2O(g)
c. C(s) + O2(g) → CO2(g)
d. 2SO2(g) + O2(g) → 2SO3(g)
e. 2NO(g) → N2(g) + O2(g) → d. 2SO2(g) + O2(g) → 2SO3(g)
The reaction of ICl with hydrogen : 2 ICl + H2 → I2 + 2 HCl
is first order in ICl and second order in H2. In an experiment to determine the rate law, the rate constant was determined to be 2.24 M-2s-1. Using this value for the rate constant, the rate of the reaction when [ICl] = 0.314M and [H2] = 0.179M would be:
a. 1.26 x 10-3 Ms-1
b. 2.25 x 10-2 Ms-1
c. 3.95 x 10-2 Ms-1
d. 2.23 x 102 Ms-1
e. 2.52 x 10-1 Ms-1 → a. decrease by 3/4