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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 27c
Consider the reaction:
2 HBr (g) → H2 (g) + Br2 (g)
c. If the volume of the reaction vessel in part b was 1.25 L, what amount of Br2 (in moles) was formed during the first 15.0 s of the reaction?
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 29a
For the reaction 2 A(g) + B(g) → 3 C(g), a. Determine the expression for 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.
- What is the rate of formation of C2H4 between 20 and 30 seconds for the reaction: C4H8(g) → 2 C2H4(g), given the tabulated data collected for the concentration of C4H8 as a function of time?
Problem 33
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(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
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 35b
Consider the reaction: H2( g) + Br2( g) → 2 HBr( g) The graph shows the concentration of Br2 as a function of time.
b. Make a rough sketch of a curve representing the concentration of HBr as a function of time. Assume that the initial concentration of HBr is zero
- 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 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?