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- The reaction 2 H2O2(aq) → 2 H2O(l) + O2(g) is first order in H2O2 and under certain conditions has a rate constant of 0.00752 s⁻¹ at 20.0 °C. A reaction vessel initially contains 150.0 mL of 30.0% H2O2 by mass solution (the density of the solution is 1.11 g/mL). The gaseous oxygen is collected over water at 20.0 °C as it forms. What volume of O2 forms in 85.0 seconds at a barometric pressure of 742.5 mmHg? (The vapor pressure of water at this temperature is 17.5 mmHg.)
Problem 1
- What is the half-life for this reaction at the initial concentration?
Problem 9
- How old is a rock that contains 83.2% of the amount of uranium-238 it contained when it was formed?
Problem 11
Problem 27a
Consider the reaction:
2 HBr (g) → H2 (g) + Br2 (g)
a. Express the rate of the reaction in terms of the change in concentration of each of the reactants and products.
Problem 27b
Consider the reaction:
2 HBr (g) → H2 (g) + Br2 (g)
b. In the first 20.0 s of this reaction, the concentration of HBr dropped from 0.600 M to 0.512 M. Calculate the average rate of the reaction during this time interval.
Problem 28a
Consider the reaction: 2 N2O( g) → 2 N2(g) + O2(g) a. Express the rate of the reaction in terms of the change in concentration of each of the reactants and products.
Problem 29b
For the reaction 2 A(gg) + B(g) → 3 C(g), b. when A is decreasing at a rate of 0.200 M/s, how fast is B decreasing? How fast is C increasing?
- Is this the correct formulation for the task of completing the table for the reaction: Cl2(g) + 3 F2(g) → 2 ClF3(g)?
Problem 31
Problem 32
Consider the reaction: 8 H2S(g) + 4 O2(g) → 8 H2O(g) + S8(g) Complete the table.
Problem 33a
Consider the reaction: C4H8( g) → 2 C2H4( g) The tabulated data were collected for the concentration of C2H4 as a function of time: a. What is the average rate of the reaction between 0 and 10 s? Between 40 and 50 s?
Problem 34a
Consider the reaction: NO2(g) → NO(g) + 1/2 O2(g) The tabulated data were collected for the concentration of NO2 as a function of time: a. What is the average rate of the reaction between 10 and 20 s? Between 50 and 60 s?
Problem 34b
Consider the reaction: NO2(g) → NO(g) + 1/2 O2( g) The tabulated data were collected for the concentration of NO2 as a function of time: b. What is the rate of formation of O2 between 50 and 60 s?
Problem 35a(i)
Consider the reaction: H2(g) + Br2(g) → 2 HBr(g) The graph shows the concentration of Br2 as a function of time.
a. Use the graph to calculate each quantity: (i) the average rate of the reaction between 0 and 25 s
Problem 35a(ii)
Consider the reaction: H2(g) + Br2(g) → 2 HBr(g). The graph shows the concentration of Br2 as a function of time. a. Use the graph to calculate each quantity: (ii) the instantaneous rate of the reaction at 25 s.
Problem 35a(iii)
Consider the reaction: H2(g) + Br2(g) → 2 HBr(g) The graph shows the concentration of Br2 as a function of time. a. Use the graph to calculate each quantity: (iii) the instantaneous rate of formation of HBr at 50 s
- Consider the reaction: 2 H2O2(aq) → 2 H2O(l) + O2(g). The graph shows the concentration of H2O2 as a function of time. Use the graph to calculate each quantity: a. the average rate of the reaction between 10 and 20 seconds, b. the instantaneous rate of the reaction at 30 seconds.
Problem 36
Problem 36d
Consider the reaction: 2 H2O2(aq) → 2 H2O(l ) + O2( g) The graph shows the concentration of H2O2 as a function of time. Use the graph to calculate each quantity: d. If the initial volume of the H2O2 is 1.5 L, what total amount of O2 (in moles) is formed in the first 50 s of reaction?
Problem 37a
This graph shows a plot of the rate of a reaction versus the concentration of the reactant A for the reaction A → products. a. What is the order of the reaction with respect to A?
Problem 37c
This graph shows a plot of the rate of a reaction versus the concentration of the reactant A for the reaction A → products. c. Write a rate law for the reaction including an estimate for the value of k.
Problem 38a
This graph shows a plot of the rate of a reaction versus the concentration of the reactant.
a. What is the order of the reaction with respect to A?
Problem 38b
This graph shows a plot of the rate of a reaction versus the concentration of the reactant.
b. Make a rough sketch of a plot of [A] versus time
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 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?