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Asked by Manuel Zahn
on 30 Nov 2012

% Calculation of the chemical degradation rate k of a substance based on slope and intercept of the Arrhenius Plot ln k = slope * (1/T) + intercept

clear, clc close all % 1/T [°K] at 5°C kelv=273.16; temp5=5+kelv; x1=1/temp5; % slope of Arrhenius Plot slopeA=-8729.3; % intercept of Arrhenius Plot interc=29.928; % Degradation rate k at temperature T lnk5=(slopeA*x1)+interc k5=exp(lnk5)

The result is k=0.2336 [per month] calculated using MATLAB but 0.2237 if calculated using a simple calculator! I am lost ...

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Answer by Image Analyst
on 30 Nov 2012

I get this:

lnk5 = -1.45429795800977 k5 = 0.233564278287803

Seems to be different than what you got. But I had:

format longg; format compact;

in the script before your code. Have you seen the FAQ: http://matlab.wikia.com/wiki/FAQ#Why_does_MATLAB_only_calculate_to_4_significant_digits.3F

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