5 Written Questions
5 Matching Questions
- 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)
- Evaluate the specific rate constant for this reaction at 800°C. The rate-law expression is rate = k[NO]2[H2]. (Choose the closest answer.)
2NO(g) + 2H2(g) → N2(g) + 2H2O(g)
Experiment Initial [NO] Initial [H2] Initial Rate of Reaction (M•s−1)
1 0.0010 M 0.0060 M 7.9 × 10−7
2 0.0040 M 0.0060 M 1.3 × 10−5
3 0.0040 M 0.0030 M 6.4 × 10−6
a. 22 M−2•s−1
b. 4.6 M−2•s−1
c. 1.3 × 102 M−2•s−1
d. 0.82 M−2•s−1
e. 0.024 M−2•s−1
- 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
- A catalyst
a. increases the amount of products present at equilibrium.
b. increases the rate at which equilibrium is reached but decreases the equilibrium constant.
c. increases the rate at which equilibrium is reached without changing the equilibrium constant.
d. increases ΔH for the process.
e. lowers ΔS for the process.
- Which of the following statements regarding temperature and reaction rate is false.
a. The Arrhenius equation can be used to find the activation energy of a reaction.
b. Reaction rate always increases with higher temperature.
c. A larger negative value of ΔG0 causes a faster reaction rate.
d. A larger value of Ea causes a slower reaction rate.
e. The rate constant for a reaction decreases at lower temperatures.
- a c. increases the rate at which equilibrium is reached without changing the equilibrium constant.
- b d. 4.8 × 103 seconds
- c c. CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
- d c. 1.3 × 102 M−2•s−1
- e c. A larger negative value of ΔG0 causes a faster reaction rate
5 Multiple Choice Questions
- b. 300°K
- d. 1.8 M•s−1
- e. The slow step will only include reactants listed in the overall chemical equation.
- b. The specific rate constant for a zero-order reaction is independent of temperature.
- d. Their values get larger as the temperature is increased.
5 True/False Questions
If a reaction is second-order with respect to a particular reactant, when the concentration of that reactant is increased by a factor of 2, the reaction rate will _____.
a. increase by a factor of 4.
b. remain constant.
c. decrease by a factor of .
d. increase by a factor of 2.
e. decrease by a factor of . → c. 3.04 mol/L•min
Suppose a reaction A + B → C occurs at some initial rate at 25°C. Which response includes all of the changes below that could increase the rate of this reaction?
I. lowering the temperature
II. adding a catalyst
III. increasing the initial concentration of B
d. I and II
e. II and III → e. II and III
The rate constant for a first-order reaction is 1.4 × 10-2 s-1 at 716 K and 5.5 × 10-2 s-1 at 864 K. What is the activation energy?
a. 27 kJ/mol
b. 21 kJ/mol
c. 47 kJ/mol
d. 5700 kJ/mol
e. 48 kJ/mol → b. 54.5 s−1
Given the following data for the reaction below.
NH4+ + NO2− → N2 + 2H2O
Trial [NH4+] [NO2−] Rate
1 0.010 M 0.030 M 0.020 M/s
2 0.015 0.030 0.030
3 0.010 0.015 0.005
The rate law for the reaction is
a. rate = k[NH4+][NO2−]
b. rate = k[NH4+]2[NO2−]
c. rate = k[NH4+][NO2−]2
d. rate = k[NH4+]2[NO2−]2
e. None of these → d. rate = k[A]2[C]
In the following reaction, the rate of formation of NH3 is 0.15 mol/L•min. What is the rate of reaction?
N2 + 3H2 → 2NH3
a. 0.15 mol/L•min
b. 0.075 mol/L•min
c. −0.075 mol/L•min
d. 0.20 mol/L•min
e. 0.30 mol/L•min → a. 0.30 mol/L•s