QUESTION 1 Radioactive decay is a process that follows first-order kinetics. The half-life of 241 pu is 13.00 years; how long (in hours) would it take for the amount of 241 Pu to decrease to 49.48% of its initial amount? Key Concept: Half-life for first order reaction. t = 0.693/k. Strategy: Determine rate constant and then calculate time using integrated first order rate law.

QUESTION 1 Radioactive decay is a process that follows first-order kinetics. The half-life of 241 pu is 13.00 years; how long (in hours) would it take for the amount of 241 Pu to decrease to 49.48% of its initial amount? Key Concept: Half-life for first order reaction. t = 0.693/k. Strategy: Determine rate constant and then calculate time using integrated first order rate law.

Chemistry & Chemical Reactivity

9th Edition

ISBN:9781133949640

Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Publisher:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Chapter14: Chemical Kinetics: The Rates Of Chemical Reactions

Section: Chapter Questions

Problem 5PS: Experimental data are listed here for the reaction A 2 B. (a) Prepare a graph from these data;...

See similar textbooks

Similar questions

11.41 For a drug to be effective in treating an illness, its levels in the bloodstream must be maintained for a period of time. One way to measure the level of a drug in the body is to measure its rate of appearance in the urine. The rate of excretion of penicillin is first order, with a half-life of about 30 min. If a person receives an injection of 25 mg of penicillin at t = 0, how much penicillin remains in the body after 3 hours?
What is the difference between average rate, initial rate, and instantaneous rate?
A study of the rate of the reaction represented as 2AB gave the following data: Time (s) 0.0 5.0 10.0 15.0 20.0 25.0 35.0 [A](M) 1.00 0.775 0.625 0.465 0.350 0.205 0.230 (a) Determine the average rate of disappearance of A between 0.0 s and 10.0 s, and between 10.0 s and 20.0 s. (b) Estimate the instantaneous rate of disappearance of A at 15.0 s from a graph of time versus [A]. What are theunits of this rate? (c) Use the rates found in parts (a) and (b) to determine the average rate of formation of B between 0.00 s and 10.0 s, and the instantaneous rate of formation of B at 15.0 s.
A certain reaction has the form aAProducts At a particular temperature, concentration versus time data were collected. A plot of 1/ [A] versus Lime (in seconds) gave a straight line with a slope of 6.90 102. What is the differential rate law for this reaction? What is the integrated rate law for this reaction? What is the value of the rate constant for this reaction? If [A]0 for this reaction is 0.100 M, what is the first half-life (in seconds)? If the original concentration (at t = 0) is 0.100 M, what is the second half-life (in seconds)?
As with any drug, aspirin (acetylsalicylic acid) must remain in the bloodstream long enough to be effective. Assume that the removal of aspirin from the bloodstream into the urine is a lirst-order reaction, with a half-life of about 3 hours. The instructions on an aspirin bottle say to take 1 or 2 tablets every 4 hours. If a person takes 2 aspirin tablets, how much aspirin remains in the bloodstream when it is time for the second dose? (A standard tablet contains 325 mg of aspirin.)
Experimental data are listed here for the reaction A 2 B. (a) Prepare a graph from these data; connect the points with a smooth line; and calculate the rate of change of [B] for each 10-second interval from 0.0 to 40.0 seconds. Does the rate of change decrease from one time interval to the next? Suggest a reason for this result. (b) How is the rate of change of [A] related to the rate of change of [B] in each time interval? Calculate the rate of change of [A] for the time interval from 10.0 to 20.0 seconds.
Phenyl acetate, an ester, reacts with water according to the equation The data in the table were collected for this reaction at 5 C. (a) Plot the phenyl acetate concentration versus time, and describe the shape of the curve observed. (b) Calculate the rate of change of the phenyl acetate concentration during the period 15.0 seconds to 30.0 seconds and also during the period 75.0 seconds to 90.0 seconds. Why is one value smaller than the other?
Experimental data are listed here for the reaction A 2 B. (a) Prepare a graph from these data; connect the points with a smooth line; and calculate the rate of change of [B] for each 10-second interval from 0.0 to 40.0 seconds. Does the rate of change decrease from one time interval to the next? Suggest a reason for this result. (b) How is the rate of change of [A] related to the rate of change of [B] in each time interval? Calculate the rate of change of [A] for the time interval from 10.0 to 20.0 seconds.
Experiments have shown that the average frequency of chirping by a snowy tree cricket (Oecanthus fultoni) depends on temperature as shown in the table. Chirping Rate (per min) Temperature (C) 178 25.0 126 20.3 100. 17.3 What is the apparent activation energy of the process that controls the chirping? What is the rate of chirping expected at a temperature of 7.5C?
When formic acid is heated, it decomposes to hydrogen and carbon dioxide in a first-order decay: HCOOH(g)CO2(g)+H2(g) The rate of reaction is monitored by measuring the total pressure in the reaction container. Time (s) Pressure (torr) 0 220 50 324 100 379 150 408 200 423 250 431 300 435 Calculate the rate constant and half-life in seconds for the reaction. At the start of the reaction (time = 0), only formic acid is present. (HINT: Find the partial pressure of formic acid using Dalton's law of partial pressure and the reaction stoichiometry to find PHCOOH at each time.)