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Problem 25b
(b) The reaction 2 NO1g2 + Cl21g2¡2 NOCl1g2 is carried out in a closed vessel. If the partial pressure of NO is decreasing at the rate of 56 torr/min, what is the rate of change of the total pressure of the vessel?
- (b) The rate of decrease in N2H4 partial pressure in a closed reaction vessel from the reaction N2H4(g) + H2(g) → 2 NH3(g) is 74 torr per hour. What are the rates of change of NH3 partial pressure and total pressure in the vessel?
Problem 26
Problem 27a
A reaction A + B → C obeys the following rate law: Rate = k[B]2. (a) If [A] is doubled, how will the rate change? Will the rate constant change?
Problem 27b
A reaction A + B → C obeys the following rate law: Rate = k[B]2. (b) What are the reaction orders for A and B? What is the overall reaction order?
Problem 27c
A reaction A + B → C obeys the following rate law: Rate = k[B]2. (c) What are the units of the rate constant?
Problem 28a
Consider a hypothetical reaction between A, B, and C that is first order in A, zero order in B, and second order in C. (a) Write the rate law for the reaction.
Problem 28b,c,d,f
Consider a hypothetical reaction between A, B, and C that is first order in A, zero order in B, and second order in C. (b) How does the rate change when [A] is doubled and the other reactant concentrations are held constant? (c) How does the rate change when [B] is tripled and the other reactant concentrations are held constant? (d) How does the rate change when [C] is tripled and the other reactant concentrations are held constant? (f) By what factor does the rate change when the concentrations of all three reactants are cut in half?
Problem 28e
Consider a hypothetical reaction between A, B, and C that is first order in A, zero order in B, and second order in C. (e) By what factor does the rate change when the concentrations of all three reactants are tripled?
Problem 29a
The decomposition reaction of N2O5 in carbon tetrachloride is 2 N2O5 → 4 NO2 + O2. The rate law is first order in N2O5. At 64°C the rate constant is 4.82 × 10-3 s-1. (a) Write the rate law for the reaction.
Problem 29c,d
The decomposition reaction of N2O5 in carbon tetrachloride is 2 N2O5 → 4 NO2 + O2. The rate law is first order in N2O5. At 64°C the rate constant is 4.82 × 10-3 s-1. (c) What happens to the rate when the concentration of N2O5 is doubled to 0.0480 M? (d) What happens to the rate when the concentration of N2O5 is halved to 0.0120 M?
Problem 30d
Consider the following reaction: 2 NO1g2 + 2 H21g2¡N21g2 + 2 H2O1g2 (d) What is the reaction rate at 1000 K if [NO] is decreased to 0.010 M and 3H24 is increased to 0.030 M?
Problem 32a
The reaction between ethyl bromide (C2H5Br) and hydroxide ion in ethyl alcohol at 330 K, C2H5Br(alc) + OH-(alc) → C2H5OH(l) + Br-(alc), is first order each in ethyl bromide and hydroxide ion. When [C2H5Br] is 0.0477 M and [OH-] is 0.100 M, the rate of disappearance of ethyl bromide is 1.7×10-7 M/s. (a) What is the value of the rate constant?
Problem 32b
The reaction between ethyl bromide (C2H5Br) and hydroxide ion in ethyl alcohol at 330 K, C2H5Br(alc) + OH-(alc) → C2H5OH(l) + Br-(alc), is first order each in ethyl bromide and hydroxide ion. When [C2H5Br] is 0.0477 M and [OH-] is 0.100 M, the rate of disappearance of ethyl bromide is 1.7×10-7 M/s. (b) What are the units of the rate constant?
Problem 32c
The reaction between ethyl bromide (C2H5Br) and hydroxide ion in ethyl alcohol at 330 K, C2H5Br(alc) + OH-(alc) → C2H5OH(l) + Br-(alc), is first order each in ethyl bromide and hydroxide ion. When [C2H5Br] is 0.0477 M and [OH-] is 0.100 M, the rate of disappearance of ethyl bromide is 1.7×10-7 M/s. (c) How would the rate of disappearance of ethyl bromide change if the solution were diluted by adding an equal volume of pure ethyl alcohol to the solution?
Problem 33a
The iodide ion reacts with hypochlorite ion (the active ingredient in chlorine bleaches) in the following way: OCl- + I- → OI- + Cl- . This rapid reaction gives the following rate data:
[OCl4-] (M) [I-] (M) Initial Rate (M,s)
1.5 * 10-3 1.5 * 10-3
1.36 * 10-4 3.0 * 10-3 1.5 * 10-3 2.72 * 10-4
1.5 * 10-3 3.0 * 10-3 2.72 * 10-4
(a) Write the rate law for this reaction.
Problem 33b
The iodide ion reacts with hypochlorite ion (the active ingredient in chlorine bleaches) in the following way: OCl - + I - ¡OI - + Cl - . This rapid reaction gives the following rate data:
[OCl4-] (M) [I-] (M) Initial Rate (M,s)
1.5 * 10-3 1.5 * 10-3
1.36 * 10-4 3.0 * 10-3 1.5 * 10-3 2.72 * 10-4
1.5 * 10-3 3.0 * 10-3 2.72 * 10-4
(b) Calculate the rate constant with proper units.
Problem 33c
The iodide ion reacts with hypochlorite ion (the active ingredient in chlorine bleaches) in the following way: OCl- + I- → OI- + Cl- . This rapid reaction gives the following rate data:
[OCl4-] (M) [I-] (M) Initial Rate (M,s)
1.5 * 10-3 1.5 * 10-3
1.36 * 10-4 3.0 * 10-3 1.5 * 10-3 2.72 * 10-4
1.5 * 10-3 3.0 * 10-3 2.72 * 10-4 (c) Calculate the rate when [OCl-] = 2.0 * 10-3 M and [I-] = 5.0 * 10 - 4 M.
- The reaction 2 ClO2(aq) + 2 OH-(aq) → ClO3-(aq) + ClO2-(aq) + H2O(l) was studied with the following results: Experiment [ClO2] (M) [OH-] (M) Initial Rate (M/s) 1 0.060 0.030 0.0248 2 0.020 0.030 0.00276 3 0.020 0.090 0.00828. (c) Calculate the rate when [ClO2] = 0.100 M and [OH-] = 0.050 M.
Problem 34
Problem 35b
The following data were measured for the reaction BF3(g) + NH3(g) → F3BNH3(g):
Experiment [BF3] (M) [NH3] (M) Initial Rate (M/s)
1 0.250 0.250 0.2130
2 0.250 0.125 0.1065
3 0.200 0.100 0.0682
4 0.350 0.100 0.1193
5 0.175 0.100 0.0596
(b) What is the overall order of the reaction?
Problem 35c
The following data were measured for the reaction BF3(g) + NH3(g) → F3BNH3(g):
Experiment [BF3] (M) [NH3] (M) Initial Rate (M/s)
1 0.250 0.250 0.2130
2 0.250 0.125 0.1065
3 0.200 0.100 0.0682
4 0.350 0.100 0.1193
5 0.175 0.100 0.0596
(c) Calculate the rate constant with proper units?
- The following data were collected for the rate of disappearance of NO in the reaction 2 NO(g) + O2(g) → 2 NO2(g): Experiment [NO] (M) [O2] (M) Initial Rate (M/s) 1 0.0126 0.0125 1.41 * 10^-2 2 0.0252 0.0125 5.64 * 10^-2 3 0.0252 0.0250 1.13 * 10^-1 (d) What is the rate of disappearance of NO when [NO] = 0.0750 M and [O2] = 0.0100 M? (e) What is the rate of disappearance of O2 at the concentrations given in part (d)?
Problem 36
- Consider the gas-phase reaction between nitric oxide and bromine at 273 _x001E_C: 2 NO(g) + Br2(g) → 2 NOBr(g). The following data for the initial rate of appearance of NOBr were obtained: Experiment [NO] (M) [Br2] (M) Initial Rate (M/s) 1 0.10 0.20 24 2 0.25 0.20 150 3 0.10 0.50 60 4 0.35 0.50 735 (c) How is the rate of appearance of NOBr related to the rate of disappearance of Br2? (d) What is the rate of disappearance of Br2 when [NO] = 0.075 M and [Br2] = 0.25 M?
Problem 37
- Consider the reaction of peroxydisulfate ion S2O8^2- with iodide ion I^- in aqueous solution: S2O8^2- (aq) + 3 I^- (aq) → 2 SO4^2- (aq) + I3^- (aq). At a particular temperature, the initial rate of disappearance of S2O8^2- varies with reactant concentrations in the following manner: Experiment S2O8^2- [M] I^- [M] Initial Rate [M/s] 1 0.018 0.036 2.6 * 10^-6 2 0.027 0.036 3.9 * 10^-6 3 0.036 0.054 7.8 * 10^-6 4 0.050 0.072 1.4 * 10^-5 (b) What is the average value of the rate constant for the disappearance of S2O8^2- based on the four sets of data? (c) How is the rate of disappearance of S2O8^2- related to the rate of disappearance of I^-? (d) What is the rate of disappearance of I^- when [S2O8^2-] = 0.025 M and [I^-] = 0.050 M?
Problem 38
Problem 38a
Consider the reaction of peroxydisulfate ion (S2O82-) with iodide ion (I-) in aqueous solution:
S2O82-(aq) + 3 I-(aq) → 2 SO42-(aq) + I3-(aq)
At a particular temperature, the initial rate of disappearance of S2O82- varies with reactant concentrations in the following manner:
Experiment [S2O82-] (M) [I-] (M) Initial Rate (M/s)
1 0.018 0.036 2.6 × 10-6
2 0.027 0.036 3.9 × 10-6
3 0.036 0.054 7.8 × 10-6
4 0.050 0.072 1.4 × 10-5
(a) Determine the rate law for the reaction and state the units of the rate constant.
Problem 39a
(a) For the generic reaction A → B what quantity, when graphed versus time, will yield a straight line for a first-order reaction?
Problem 41a
(a) The gas-phase decomposition of SO2Cl2, SO2Cl2(g) → SO2(g) + Cl2(g), is first order in SO2Cl2. At 600 K the half-life for this process is 2.3 × 105 s. What is the rate constant at this temperature?
Problem 41b
(b) At 320°C the rate constant is 2.2 × 10-5 s-1. What is the half-life at this temperature?
- Molecular iodine, I2(g), dissociates into iodine atoms at 625 K with a first-order rate constant of 0.271 s-1. (b) If you start with 0.050 M I2 at this temperature, how much will remain after 5.12 s assuming that the iodine atoms do not recombine to form I2?
Problem 42
Problem 43a
As described in Exercise 14.41, the decomposition of sulfuryl chloride (SO2Cl2) is a first-order process. The rate constant for the decomposition at 660 K is 4.5 × 10-2 s-1. (a) If we begin with an initial SO2Cl2 pressure of 450 torr, what is the partial pressure of this substance after 60 s?
Problem 43b
As described in Exercise 14.41, the decomposition of sulfuryl chloride (SO2Cl2) is a first-order process. The rate constant for the decomposition at 660 K is 4.5 × 10-2 s-1. (b) At what time will the partial pressure of SO2Cl2 decline to one-tenth its initial value?