A reaction is known to follow first-order kinetics. What is the half-life (in seconds) if it takes (7.96x10^2) seconds for the concentration of the only reactant to drop from (3.460x10^0) M to (3.470x10^-1) M? Enter your answer in scientific notation with 3 sig figs. Do not include any units in your answer. Do not round any intermediate calculations. Note: Your answer is assumed to be reduced to the highest power possible.

A reaction is known to follow first-order kinetics. What is the half-life (in seconds) if it takes (7.96x10^2) seconds for the concentration of the only reactant to drop from (3.460x10^0) M to (3.470x10^-1) M? Enter your answer in scientific notation with 3 sig figs. Do not include any units in your answer. Do not round any intermediate calculations. Note: Your answer is assumed to be reduced to the highest power possible.

Chemistry: Principles and Practice

3rd Edition

ISBN:9780534420123

Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Publisher:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Chapter13: Chemical Kinetics

Section: Chapter Questions

Problem 13.50QE

See similar textbooks

Similar questions

The hydrolysis of the sugar sucrose to the sugars glucose and fructose, C12H22O11+H2OC6H12O6+C6H12O6 follows a first-order rate equation for the disappearance of sucrose: Rate =k[C12H22O11] (The products of the reaction, glucose and fructose, have the same molecular formulas but differ in the arrangement of the atoms in their molecules.) (a) In neutral solution, k=2.11011s1 at 27 C and 8.51011s1 at 37 C. Determine the activation energy, the frequency factor, and the rate constant for this equation at 47 C (assuming the kinetics remain consistent with the Arrhenius equation at this temperature). (b) When a solution of sucrose with an initial concentration of 0.150 M reaches equilibrium, the concentration of sucrose is 1.65107M . How long will it take the solution to reach equilibrium at 27 C in the absence of a catalyst? Because the concentration of sucrose at equilibrium is so low, assume that the reaction is irreversible. (c) Why does assuming that the reaction is irreversible simplify the calculation in pan (b)?
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.)
Make a graph of [A] versus time for zero-, first-, and second-order reactions. From these graphs, compare successive half-lives.
What is the difference between average rate, initial rate, and instantaneous rate?
6. Phenyl acetate, an ester, reacts with water according to the equation The data in the table were collected for this reaction at 5°C. Time (s) [Phenyl acetate] (mol/L) 0 0.55 15.0 0.42 30.0 0.31 45.0 0.23 60.0 0.17 75.0 0.12 90.0 0.085 Plot the phenyl acetate concentration versus time, and describe the shape of the curve observed. 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? What is the rate of change of the phenyl acetate concentration during the time period 60.0 seconds to 75.0 seconds? What is the instantaneous rate at 15.0 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?
When formic acid is heated, it decomposes to hydrogen and carbon dioxide in a first-order decay. HCOOH(g) CO2(g) + H2(g) At 550 C, the half-life of formic acid is 24.5 minutes. (a) What is the rate constant, and what are its units? (b) How many seconds are needed for formic acid, initially 0.15 M, to decrease to 0.015 M?
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.)
If you know some calculus, derive the integrated first-order rate law for the reaction by following these steps: Define the reaction rate in terms of [A]. Write the rate law in terms of [A], k, and t. Separate variables in the rate law. Integrate the rate law. Write the integrated equation in the form . Derive the half-life as was done in Section 11-3c.
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.
11.48 The following data were collected for the decomposition of NT),-: Time, f (min) [N2Os] (mol L-1) 0 0.200 5 0.171 10 0.146 15 0.125 20 0.106 25 0.0909 30 0.0777 35 0.0664 40 0.0570 Use appropriate graphs to determine the rate constant for this reaction. Find the half-life of the reaction.