New Highlights on Analyzing First-Order Kinetic Data of the Peroxodisulfate-lodide System at Different Temperatures

摘要

Recently three articles (1-3)have been published examining the analysis problems of pseudo first-order kinetics and its use for undergraduates.The work by Hemalatha and NoorBatcha (1)compares three methods at one temperature using the peroxodisulfate-iodide system to determine the rate constant,k,and the absorption value at infinite time,A_(infinity).The so-called "conventional method" (method I)requires measurements at time of completion if linear regression is used (for nonlinear regression this is not needed)and of course measurements at various time intervals.The two other methods are the so-called "time-lag methods" of Guggenheim (4)(method II)and a similar method proposed by a number of authors (5-7)(method III).The latter methods used grouped kinetic data,separated by a fixed time interval and no measurement at time of completion is required.This last requirement enables the lab to be completed within the lab period.