5 Written questions
5 Matching questions
- A molecule of ethyl alcohol is converted to acetaldehyde in one's body by zero order kinetics. If the concentration of alcohol is 0.015 mol/L and the rate constant = 6.4 × 10−5 mol/L•min, what is the concentration of alcohol after 3.5 hours?
a. 0.0016 mol/L
b. 9.6 × 107 mol/L
c. 4.3 × 10−3 mol/L
d. 0.15 mol/L
e. 0.0032 mol/L
- In a reaction coordinate diagram, reacting molecules are most unstable ______.
a. at their initial position c. right after they collide
b. when they are about to collide d. at the transition state
- 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
- Consider the hypothetical reaction shown below.
2A + C2 → A2C + C
Assume that the following proposed mechanism is consistent with the rate data.
A + C2 → AC + C slow
AC + A → A2C fast
2A + C2 → A2C + C overall
Which one of the following statements must be true? The reaction is ____.
a. first order in A, first order in B, and third order overall
b. second order in C2 and second order overall
c. first order in A and first order in C2
d. second order in C2, zero order in A, and third order overall
e. second order in A and second order overall
- 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
- a b. 2.01 min−1
- b c. 1.3 × 102 M−2•s−1
- c c. first order in A and first order in C2
- d a. 0.0016 mol/L
- e d. at the transition state
5 Multiple choice questions
- d. rate = k[NO]2[Cl2]
- d. k[H2][CO]
- b. 8.4 M−2⋅s−1
- b. 0.00648 M
- d. 4.8 × 103 seconds
5 True/False questions
Which of the following statements regarding collision and transition state theory is false?
a. Reactants must collide to form products.
b. All reactant collisions result in product formation.
c. Activation energy is always positive.
d. Reactant molecules must absorb energy to form the transition state.
e. Reactant collisions must be oriented properly to form products. → c. A larger negative value of ΔG0 causes a faster reaction rate
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 → d. 47.1 kJ/mol
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 → e. 58.5 s
Which of the following is a kinetic quantity?
b. internal energy
c. free energy
d. rate of reaction
e. entropy → d. rate of reaction
The oxidation of NO by O3 is first order in each of the reactants, and its rate constant is 1.5 × 107 M−1•s−1. If the concentrations of NO and O3 are each 5.0 × 10−7 M, what is the rate of oxidation of NO in M•s−1?
a. 3.8 × 10−6
b. 2.5 × 10−14
c. 7.5 × 10−7
e. 7.5 → d. 525