Given a kinetic rate at a reference temperature (argument tkref)
this function calculates its temperature-scaling factor
following Arrhenius kinetics.
ftemp_arrh(tk, dha, tkref = 298.15)Arguments
- tk
Temperature (Kelvin)
- dha
Activation energy (J mol-1)
- tkref
Reference temperature (Kelvin)
Value
A numeric value for \(f\)
Details
To correct for effects by temperature following Arrhenius kinetics,
and given a reference temperature \(T_0\), \(f\) calculates the temperature
scaling. Arrhenius kinetics are described by an equation of form
\(x(T)= exp(c - \Delta H_a / (T R))\). The temperature-correction
function \(f(T, \Delta H_a)\) is thus given by \(f=x(T)/x(T_0)\) which is:
$$
f = exp( \Delta H_a (T - T_0) / (T_0 R T_K) )
$$
\(\Delta H_a\) is given by argument dha. \(T\) is given by argument
tk and has to be provided in Kelvin. \(R\) is the universal gas constant
and is 8.3145 J mol-1 K-1. Note that this is equivalent to
$$
f = exp( (\Delta H_a/R) (1/T_0 - 1/T) )
$$
Examples
# Relative rate change from 25 to 10 degrees Celsius (percent change)
print( (1.0-ftemp_arrh( 283.15, 100000, tkref = 298.15))*100 )
#> [1] 88.19912