5 Written Questions
5 Matching Questions
- #127 graph
- The gas phase reaction A + B → C has a reaction rate which is experimentally observed to follow the relationship rate = k[A]2[B]. Which one of the following would affect the value of the specific rate constant, k?
a. increasing the temperature
b. changing the concentration of A
c. changing the concentration of B
d. changing the concentration of C
e. all of these
- Calculate the activation energy of a reaction if the rate constant is 0.75 s−1 at 25°C and 11.5 s−1 at 75°C.
a. 681 J/mol
b. 20.4 kJ/mol
c. 15.8 kJ/mol
d. 47.1 kJ/mol
e. 31.4 kJ/mol
- Which of the following statements regarding the rate constant in the rate law expression is incorrect?
a. Its value increases with temperature.
b. Its value is independent of initial concentration at a given temperature.
c. Its units depend on the overall order of reaction.
d. Its value is experimentally determined.
e. The larger its value, the slower the reaction rate.
- A troublesome reaction that is responsible in part for acid rain is
SO3 + H2O → H2SO4
Rate data have been determined at a particular temperature for the reaction in which all reactants and products are gases.
Trial Run Initial [SO3] Initial [H2O] Initial Rate (M•s−1)
1 0.35 M 0.35 M 0.150
2 0.70 M 0.35 M 0.600
3 0.35 M 0.70 M 0.300
4 0.70 M 0.70 M 1.20
The rate-law expression is ____.
a. rate = k[SO3]2[H2O]2
b. rate = k[SO3]2[H2O]
c. rate = k[SO3][H2O]2
d. rate = k[SO3]2
e. rate = k[SO3][H2O]
- a graph
- b e. The larger its value, the slower the reaction rate.
- c b. rate = k[SO3]2[H2O]
- d a. increasing the temperature
- e d. 47.1 kJ/mol
5 Multiple Choice Questions
- b. 2.01 min−1
- a. 21 min
- c. A larger negative value of ΔG0 causes a faster reaction rate
- c. first order in A and first order in C2
5 True/False Questions
A second-order reaction starts with an initial concentration of 0.100 mol/L of the reactant. If the rate constant is 3.6 × 10-2 L/(mol · s), what is the time required to decrease the initial concentration to 0.050 mol/L?
a. 280 s
b. 420 s
c. 19.3 s
d. 1.39 s
e. 830 s → a. 280 s
Which of the following is a kinetic quantity?
b. internal energy
c. free energy
d. rate of reaction
e. entropy → b. A catalyst can make a nonspontaneous reaction spontaneous.
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 → b. 0.075 mol/L•min
Which of the following is not an example of an important, useful reaction catalyzed by transition metals and/or their oxides?
a. the Haber process for the production of ammonia
b. the contact process for the production of sulfur trioxide in producing sulfuric acid
c. the hydrogenation of unsaturated hydrocarbons
d. the reaction of leaded fuels with the catalysts in catalytic converters
e. the chlorination of benzene → d. 1 and 2
The second order reaction below has a rate constant of 5.76 M−1•min−1 at 1600 K.
2CH4 → C2H2 + 3H2
How long would it take for the concentration of CH4 to be reduced from 0.89 M to 5.25 × 10−4 M?
a. 165 hrs
b. 0.15 hrs
c. 2.75 hrs
d. 5.51 hrs
e. 9.27 hrs → a. 21 min