5 Written questions
5 Matching questions
- Rate data have been determined at a particular temperature for the overall reaction
2NO + 2H2 → Ν2 + 2H2O
in which all reactants and products are gases. The value of the specific rate constant at this temperature is ____.
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
a. 0.75 M−1•s−1
b. 7.5 M−2•s−1
c. 3.0 × 10−3 M−2•s−1
d. 3.0 × 10−4 M−1•s−1
e. 375 M−2•s−1
- Which statement is incorrect?
a. The reaction rate for a zero-order reaction is independent of concentrations.
b. The specific rate constant for a zero-order reaction is independent of temperature.
c. The half-life for a first-order reaction is independent of initial concentrations.
d. The rate law expression relates rate and concentration.
e. The integrated rate equation relates time and concentration.
- 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
- The rate constant for a reaction at 40.0°C is exactly 4 times that at 20.0°C. Calculate the Arrhenius energy of activation for the reaction.
a. 4.00 kJ/mol
b. 6.36 kJ/mol
c. 52.8 kJ/mol
d. 11.5 kJ/mol
e. none of these
- 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 d. 4.8 × 103 seconds
- b b. 7.5 M−2•s−1
- c c. 52.8 kJ/mo
- d e. 58.5 s
- e b. The specific rate constant for a zero-order reaction is independent of temperature.
5 Multiple choice questions
- b. second order in B and second order overall
- go to graph
- b. first
- b. 300°K
- b. difficult to verify experimentally.
5 True/False questions
Consider the following rate data for the reaction below at a particular temperature.
2A + 3B → Products
Experiment Initial [A] Initial [B] Initial Rate of Loss of A
1 0.10 M 0.30 M 7.20 × 10−5 M•s−1
2 0.10 M 0.60 M 1.44 × 10−4 M•s−1
3 0.20 M 0.90 M 8.64 × 10−4 M•s−1
The reaction is ____ order in A and ____ order in B.
a. first; first
b. second; first
c. first; second
d. second; second
e. third; first → e. k[A][B]2
Compounds A and B react to form C and D in a reaction that is found to be second-order overall and second-order in B. The rate constant at 30°C is 0.622 liter per mole per minute.
A + B → C + D
How many minutes does it take 4.0 × 10−2 M B (mixed with excess A) to be reduced to 3.3 × 10−2 M B?
a. 1.4 min
b. 3.6 min
c. 5.0 min
d. 6.4 min
e. 8.5 min → c. 707 s
Which one of the following statements is false?
a. In order for a reaction to occur, reactant molecules must collide with each other.
b. A catalyst alters the rate of a reaction and is neither a product nor a reactant in the overall equation.
c. According to collision theory a three-body collision is less likely than a two-body collision.
d. In reactions that are second order in one reactant and first order in another, the slow step generally involves a three-body collision of these reactants.
e. The transition state is a short-lived, high energy state, intermediate between reactants and products. → d. In reactions that are second order in one reactant and first order in another, the slow step generally involves a three-body collision of these reactants.
Which response below is not an example of how the nature of reactants affects the rate of reaction?
a. Graphite burns faster than diamond under equal conditions.
b. Coal dust burns faster than large chunks of coal.
c. Magnesium reacts faster in higher concentrations of HCl(aq).
d. Calcium reacts faster in water than magnesium.
e. White phosphorus reacts explosively on contact with air; red phosphorus does not. → c. Magnesium reacts faster in higher concentrations of HCl(aq).
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 → d. 18