(a)
Interpretation : The time should be calculated if the initial concentration of iodine is
Concept Introduction :
The integrated rate law for the second-order reaction can be shown as:
Where,
(b)
Interpretation : The initial concentration should be calculated with a half-life of
Concept Introduction :
The order of reaction can be defined as the number raised as the power of reactant molecules in the rate law of the reaction. According to rate law, the
For second order reaction:
Want to see the full answer?
Check out a sample textbook solutionChapter 16 Solutions
CHEMISTRY: THE MOLECULAR NATURE OF MATTE
- Sucrose, a sugar, decomposes in acid solution to give glucose and fructose. The reaction is first-order in sucrose, and the rate constant at 25 C is k = 0.21 h1. If the initial concentration of sucrose is 0.010 mol/L, what is its concentration after 5.0 h?arrow_forwardThe half-life of tritium, 3H, is 12.26 years. Tritium is the radioactive isotope of hydrogen. (a) What is the rate constant for the radioactive decay of tritium, in y1 and s1? (b) What percentage of the original tritium is left after 61.3 years?arrow_forwardThe decomposition of iodoethane in the gas phase proceeds according to the following equation: C2H5I(g)C2H4(g)+HI(g) At 660. K, k = 7.2 104 sl; at 720. K, k = 1.7 102 sl. What is the value of the rate constant for this first-order decomposition at 325C? If the initial pressure of iodoethane is 894 torr at 245C, what is the pressure of iodoethane after three half-lives?arrow_forward
- 11.44 A possible reaction for the degradation of the pesticide DDT to a less harmful compound was simulated in the laboratory. The reaction was found to be first order, with k = 4.0 X 10_H s"' at 25°C. What is the half-life for the degradation of DDT in this experiment, in years?arrow_forwardIn the presence of excess thiocyanate ion, SCN, the following reaction is first order in iron(III) ion, Fe3+; the rate constant is 1.27/s. Fe3+(aq)+SCN(aq)Fe(SCN)2+(aq) What is the half-life in seconds? How many seconds would be required for the initial concentration of Fe3+ to decrease to each of the following values: 25.0% left, 12.5% left, 6.25% left, 3.125% left? What is the relationship between these times and the half-life?arrow_forwardHydrogen peroxide, H2O2(aq), decomposes to H2O() and O2(g) in a reaction that is first-order in H2O2 and has a rate constant k = 1.06 103 min1 at a given temperature. (a) How long will it take for 15% of a sample of H2O2 to decompose? (b) How long will it take for 85% of the sample to decompose?arrow_forward
- The frequency factor A is 6.31 108 L mol1 s1 and the activation energy is 10. kJ/mol for the gas-phase reaction NO(g)+O3(g)NO2(g)+O2(g) which is important in the chemistry of stratospheric ozone depletion. (a) Calculate the rate constant for this reaction at 370. K. (b) Assuming that this is an elementary reaction, calculate the rate of the reaction at 370. K if [NO] = 0.0010 M and [O3] = 0.00050 M.arrow_forwardThe initial concentration of the reactant in a tirst-order reaction A —» products is 0.64 rnol/L and the half-life is 30.0 s. Calculate the concentration of the reactant exactly 60 s after initiation of the reaction. How long would it take for the concentration of the reactant to drop to one-eighth its initial value? How long would it take for the concentration of the reactant to drop to 0.040 mol/L?arrow_forwardThe decomposition of many substances on the surface of a heterogeneous catalyst shows the following behavior: How do you account for the rate law changing from first order to zero order in the concentration of reactant?arrow_forward
- The catalyzed decomposition of hydrogen peroxide is first-order in [H2O2]. It was found that the concentration of H2O2 decreased from 0.24 M to 0.060 M over a period of 282 minutes. What is the half-life of H2O2? What is the rate constant for this reaction? What is the initial rate of decomposition at the beginning of this experiment (when [H2O2] = 0.24 M)?arrow_forwardBacteria cause milk to go sour by generating lactic acid. Devise an experiment that could measure the activation energy for the production of lactic acid by bacteria in milk. Describe how your experiment will provide the information you need to determine this value. What assumptions must be made about this reaction?arrow_forwardFor a reaction involving the decomposition of Z at a certain temperature, the following data are obtained: (a) What is the order of the reaction? (b) Write the rate expression for the decomposition of Z. (c) Calculate k for the decomposition at that temperature.arrow_forward
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningGeneral Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage Learning