5 Written questions
5 Matching questions
- The gas phase reaction below obeys the rate-law expression rate = k[SO2Cl2]. At 593 K the specific rate constant is 2.2 × 10−5 s−1. A 2.0-g sample of SO2Cl2 is introduced into a closed 4.0-L container.
SO2Cl2 → SO2 + Cl2
How much time must pass in order to reduce the amount of SO2Cl2 present to 1.8 grams?
a. 7.4 × 103 seconds
b. 2.1 × 102 seconds
c. 3.5 × 102 seconds
d. 4.8 × 103 seconds
e. 5.8 × 104 seconds
- For the hypothetical reaction aA → products, the experimental data showed the following behavior (below). What is the reaction order with respect to reactant A?
a. zero order
b. first order
c. second order
d. third order
e. fourth order
- Which of the following statements about catalysts are false?
a. A catalyst lowers the activation energy.
b. A catalyst can make a nonspontaneous reaction spontaneous.
c. A catalyst speeds up both the forward and reverse reaction.
d. A catalyst speeds up the rate of reaction.
e. Catalyst are often transition metals and transition metal oxides.
- For a certain reaction, a plot of reactant concentration as a function of time gave a straight line. What is the order of this reaction?
a. Zero order
b. First order
c. Second order
d. Pseudo-first order
e. Impossible to tell from the given information
- The gas-phase reaction
2NO + 2H2 → N2 + 2H2O
has the following rate law expression, rate = k[NO]2[H2]. If the [NO] is halved and the [H2] is tripled, what change in rate is expected?
a. decrease by 3/4
b. increase by 3/4
c. increase by 3/2
d. decrease by 3/2
e. stays same
- a a. decrease by 3/4
- b a. zero order graph
- c d. 4.8 × 103 seconds
- d a. Zero order
- e b. A catalyst can make a nonspontaneous reaction spontaneous.
5 Multiple choice questions
- c. 3.04 mol/L•min
- b. 3.6 × 104 seconds
- a. 1.87 × 104 s−1
- d. 52.9 kJ/mol
- e. 6.4 × 10−3 M•s−1
5 True/False questions
Suppose the activation energy of a certain reaction is 250 kJ/mol. If the rate constant at T1 = 300 K is k1, and the rate constant at T2 = 320 K is k2, then k2/k1 = ____. (The universal gas constant = 8.314 J/mol•K.)
a. 3 × 10−29
e. 3 × 1028 → c. 55 kJ/mol
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 → b. 2.01 min−1
Determine the rate-law expression for the reaction below at the temperature at which the tabulated initial rate data were obtained. rate = ____
A + 2B + 3C → Products
Experiment Initial [A] Initial [B] Initial [C] Initial Rate of Loss of A
1 0.10 M 0.20 M 0.10 M 4.0 × 10−2 M•min−1
2 0.40 M 0.20 M 0.10 M 4.0 × 10−2 M•min−1
3 0.20 M 0.20 M 0.25 M 1.0 × 10−1 M•min−1
4 0.20 M 0.40 M 0.10 M 1.6 × 10−1 M•min−1
e. none of these → e. 9.0 × 10−2 M−2•s−1
One of the reactions that is used to produce gaseous hydrogen commercially follows. A proper expression for the rate of this reaction could be ____.
H2O(g) + CO(g) → H2(g) + CO2(g)
e. → -DH2O/Dt
Rate data have been determined at a particular temperature for the overall reaction
2NO + 2H2 → N2 + 2H2O
in which all reactants and products are gases.
Trial Run Initial [NO] Initial [H2] Initial Rate (M•s−1)
1 0.10 M 0.20 M 0.0150
2 0.10 M 0.30 M 0.0225
3 0.20 M 0.20 M 0.0600
The rate-law expression is ____.
a. rate = k[NO]2[H2]2
b. rate = k[NO][H2]2
c. rate = k[NO]2[H2]
d. rate = k[NO][H2]
e. None of these is correct. → c. rate = k[NO]2[H2]