Problem 38c
This graph shows a plot of the rate of a reaction versus the concentration of the reactant.
c. Write a rate law for the reaction including the value of k.
Problem 39b
What are the units of k for each type of reaction?
a. first-order reaction
b. second-order reaction
c. zero-order reaction
Problem 40a
This reaction is first order in N2O5: N2O5(g) → NO3(g) + NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s. a. Calculate the rate of the reaction when [N2O5] = 0.055 M
Problem 40b
This reaction is first order in N2O5: N2O5(g) → NO3(g) + NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s. b. What would the rate of the reaction be at the concentration indicated in part a if the reaction were second order? Zero order? (Assume the same numerical value for the rate constant with the appropriate units.)
Problem 43b
A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C. b. What is the overall order of the reaction?
Problem 43c
A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C c. By what factor does the reaction rate change if [A] is doubled (and the other reactant concentrations are held constant)? d. By what factor does the reaction rate change if [B] is doubled (and the other reactant concentrations are held constant)? e. By what factor does the reaction rate change if [C] is doubled? f. By what factor does the reaction rate change if the concentrations of all three reactants are doubled?
Problem 44a
A reaction in which A, B, and C react to form products is zero order in A, one-half order in B, and second order in C. a. Write a rate law for the reaction.
Problem 44e
A reaction in which A, B, and C react to form products is zero order in A, one-half order in B, and second order in C. c. By what factor does the reaction rate change if [A] is doubled (and the other reactant concentrations are held constant)? d. By what factor does the reaction rate change if [B] is doubled? e. By what factor does the reaction rate change if [C] is doubled? f. By what factor does the reaction rate change if [C] is doubled (and the other reactant concentrations are held constant)?
Problem 48
Consider the tabulated data showing the initial rate of a reaction (A → products) at several different concentrations of A. What is the order of the reaction? Write a rate law for the reaction including the value of the rate constant, k.
[A] (M) Initial Rate (M/s)
0.050 0.100
0.075 0.225
0.090 0.324
- The tabulated data were collected for this reaction: 2 NO2(g) + F2(g) → 2 NO2F(g). Write an expression for the reaction rate law and calculate the value of the rate constant, k. What is the overall order of the reaction?
Problem 49
Problem 50
The tabulated data were collected for this reaction: CH3Cl(g) + 3 Cl2(g) → CCl4( g) + 3 HCl(g)
Write an expression for the reaction rate law and calculate the value of the rate constant, k. What is the overall order of the reaction?
Problem 52a
Indicate the order of reaction consistent with each observation.
a. The half-life of the reaction gets shorter as the initial concentration is increased.
b. A plot of the natural log of the concentration of the reactant versus time yields a straight line.
Problem 52c
Indicate the order of reaction consistent with each observation c. The half-life of the reaction gets longer as the initial concentration is increased.
Problem 53
The tabulated data show the concentration of AB versus time for this reaction: AB( g)¡A( g) + B( g) Time (s) [AB] (M) 0 0.950 50 0.459 100 0.302 150 0.225 200 0.180 250 0.149 300 0.128 350 0.112 400 0.0994 450 0.0894 500 0.0812 Determine the order of the reaction and the value of the rate constant. Predict the concentration of AB at 25 s.
- The tabulated data show the concentration of cyclobutane (C4H8) versus time for this reaction: C4H8 -> 2 C2H4. Time (s) [C4H8] (M) 0 1.000 10 0.894 20 0.799 30 0.714 40 0.638 50 0.571 60 0.510 70 0.456 80 0.408 90 0.364 100 0.326. Determine the order of the reaction and the value of the rate constant. What is the rate of reaction when [C4H8] = 0.25 M?
Problem 55
Problem 56
The reaction A¡products was monitored as a function of time. The results are shown here. Time (s) [A] (M) 0 1.000 25 0.914 50 0.829 75 0.744 100 0.659 125 0.573 150 0.488 175 0.403 200 0.318 Determine the order of the reaction and the value of the rate constant. What is the rate of reaction when [A] = 0.10 M?
Problem 59a
This reaction was monitored as a function of time: A → B + C A plot of ln[A] versus time yields a straight line with slope -0.0105/s. a. What is the value of the rate constant (k) for this reaction at this temperature?
Problem 60b
This reaction was monitored as a function of time: AB → A + B A plot of 1/[AB] versus time yields a straight line with a slope of +0.25/Ms. b. Write the rate law for the reaction.
Problem 61
Silver nitrate solutions are often used to plate silver onto other metals. What is the maximum amount of silver (in grams) that can be plated out of 4.8 L of an AgNO3 solution containing 3.4% Ag by mass? Assume that the density of the solution is 1.01 g/mL.
- a. What is the half-life for the first-order decomposition of SO2Cl2 with a rate constant of 1.42 x 10^-4 s^-1? b. How long will it take for the concentration of SO2Cl2 to decrease to 25% of its initial concentration? c. If the initial concentration of SO2Cl2 is 1.00 M, how long will it take for the concentration to decrease to 0.78 M? d. If the initial concentration of SO2Cl2 is 0.150 M, what is the concentration of SO2Cl2 after 2.00 x 10^2 s? After 5.00 x 10^2 s?
Problem 61
- The decomposition of XY is second order in XY and has a rate constant of 7.02 * 10^-3 M^-1 s^-1 at a certain temperature. b. How long will it take for the concentration of XY to decrease to 12.5% of its initial concentration when the initial concentration is 0.100 M? When the initial concentration is 0.200 M? c. If the initial concentration of XY is 0.150 M, how long will it take for the concentration to decrease to 0.062 M? d. If the initial concentration of XY is 0.050 M, what is the concentration of XY after 5.0 * 10^1 s? After 5.50 * 10^2 s?
Problem 62
Problem 62a
The decomposition of XY is second order in XY and has a rate constant of 7.02⨉10-3 M-1• s-1 at a certain temperature. a. What is the half-life for this reaction at an initial concentration of 0.100 M?
Problem 63a
The half-life for the radioactive decay of U-238 is 4.5 billion years and is independent of initial concentration. How long will it take for 20% of the U-238 atoms in a sample of U-238 to decay?
Problem 63b
The half-life for the radioactive decay of U-238 is 4.5 billion years and is independent of initial concentration. If a sample of U-238 initially contained 3.2⨉1018 atoms when the universe was formed 13.8 billion years ago, how many U-238 atoms does it contain today?
Problem 64a
The half-life for the radioactive decay of C-14 is 5715 years and is independent of the initial concentration. How long does it take for 25.00% of the C-14 atoms in a sample of C-14 to decay?
Problem 64b
The half-life for the radioactive decay of C-14 is 5715 years and is independent of the initial concentration. If a sample of C-14 initially contains 1.5 mmol of C-14, how many millimoles are left after 2725 years?
Problem 65
The diagram shows the energy of a reaction as the reaction progresses. Label each blank box in the diagram.
a. reactants b. products c. activation energy (Ea) d. enthalpy of reaction (ΔHrxn)
Problem 67
The activation energy of a reaction is 44.2 kJ/mol and the frequency factor is 1.9⨉1011/ s. Calculate the rate constant of the reaction at 25 °C.
Problem 69
The rate constant (k) for a reaction was measured as a function of temperature. A plot of ln k versus 1/T (in K) is linear and has a slope of -7012 K. Calculate the activation energy for the reaction.
Problem 71
The data shown here were collected for the first-order reaction: N2O(g) → N2(g) + O(g) Use an Arrhenius plot to determine the activation barrier and frequency factor for the reaction.
Temperature (K) Rate Constant (1 , s)
800 3.24⨉10- 5
900 0.00214
1000 0.0614
1100 0.955
Ch.15 - Chemical Kinetics