Kinetic Order Determination

Determine the reaction order of a chemical reaction of the form: rate = Ao*[A]^a*[B]^b*exp(-Ea/R*T)


Updated Mon, 02 Apr 2012 14:39:31 +0000

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kinetic order determination by wide area search and model-data error minimization

kinfit attempts to determine the optimal order of reaction (a and b) of the form rate = Ao * [A]^a * [B]^b * exp(-Ea/R*T) where Ao is the pre-exponential rate constant
A and B are the component concentrations with a and b their powers to be determined Ea is the activation energy in same units as R the universal gas constant
T is the temperature(C)

kinfit will search over a range of a and b values to try and match experimental data of reaction rates (data) specified below with the model rate equation above. For each value of a and b, a value of Ao is determined by wide area iterative searching to minimize the error between the rate data and the model rate equation.

Inputs are:
Aorder and Border contain the ranges to search for a and b and number of values to use
example Aorder=[1,2,10] would look at 10 values from [A]^1 to [A]^2

Changes in Ea have the most impact when the data is spread over a wide range of temperatures. For most accurate results it is best to take all the data within the same few degrees and keep the system at low conversion to reduce the influence of heat and mass transfer effects

Experimental data for use in this program must contain the following data in columns (see example below). this is easy to paste in from excel and should have the following columns (only 1-4 are required)
1. Concentration of A Mole fraction is recommended variable Afrac
2. Concentration of B Mole fraction is recommended variable Bfrac
3. Temperature (C) variable TC
4. Rate data in moles/s of reaction in the compound of interest variable ratedat
5,6,.. Extra data such as conversions could be included for indexing or removing points based on defined criteria (such as conversion less then some value)

All data is pasted in as a block and the sub variables defined after that. you may also include other columns of data to assist in sorting or other plotting

V1.1, Steven Edmund, April 2012

Cite As

Steven Edmund (2023). Kinetic Order Determination (, MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2012a
Compatible with any release
Platform Compatibility
Windows macOS Linux

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