This tool may be used to calculate the temperature dependent values of a 1. order
chemical rate constant following the equation
k = A * (T/TR)B * exp(-EA/RT).
The calculations are done after the input of each value, however, perfoming effectively
only those calculations that are possible with the input values present.
The preexponential factor A and the temperature T must be given in any case.
For a temperature dependence following (T/TR)B,
the reference temperature TR and the exponent B must be given also.
For a temperature dependence following exp(-EA/RT) you have to type
EA/R or EA.
Type the values of the parameters from the equation for the temperature dependant rate
constant into the fields, behind which you find the corresponding unit.
In the case that a calculation or a conversion into another unit is possible, this will
be performed after the next mouse click.
Fields of parameters that are not needed should be left blank.
After the complete input of all needed parameters, the temperature,
and another mouseclick on any free space of the window or on the "calculate"
button, you may read the result.
Use the "reset" button to reset your calculation.
Move the mouse over a unit or a parameter or click on it to read its full name.
Example: The expression of the rate coefficient of the thermal decomposition
reaction N2O5 → NO2 + NO3 at high
pressure is k = 9.7·1014 (T/300)0.1
exp(-11080 K/T) s-1.
What is the value of the rate constant at 0°C ? Type the value of the
preexponetial factor "9.7e14" into the field for A, behind which you find
"s-1". As value for B type "0.1" and for the reference
temperature TR the value "300".
The value of the normalized activation energy "11080" type into the field for EA/R.
Finally, type the temperature in degrees celsius into the corresponding field. After a click
with the mouse on any free space of the window or on the "calculate" button
you may read the result
(k0°C = 2.32·10-3s-1).
- Large and small numbers are written exponentially. As example
2.3e5 = 2.3⋅105 = 230000 or
4.5e-5 = 4.5⋅10-5 = 0.000045.
- There is no warranty for the conversion. Cactus2000 is not
responsible for damage of any kind caused by wrong results.
- Please send an email if you have suggestions or if you would like to see more
conversions to be included.
© Bernd Krüger, 08.01.2009