ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Relative rate measurements using a reference compound with a well established rate constant are widely used for determining rate constants for gas-phase reactions. Linear least-squares regression is used to obtain the rate constant ratio, kA/kB, from the slope of plots of ln ([A]0/[A]t) vs. ln ([B]0/[B]t) where [A]0 and [B]0 are the initial concentrations of the reactant of interest, A, and of the reference compound, B, respectively, and the subscript “t” denotes the corresponding concentrations at time t. Linear least-squares analysis which does not take into account random errors in both [A] and [B] may lead to a small but systematic bias in the relative rate constant obtained from the slope of such plots. The magnitude of this bias was explored using Monte Carlo simulations. It is shown that although the bias is small for typical reaction conditions, of the order of a few percent, it can be of the same order of magnitude as the measured precision of most relative rate experiments. An algorithm for the analysis of such experiments which takes into account errors in both [A] and [B] and which avoids this systematic bias is discussed. © 1997 John Wiley & Sons, Inc.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
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