The activation energy, Ea, for a particular reaction is 13.6 kJ/mol. If the rate constant at 754 °C is 24.5/min, at what temperature (in °C) will the rate constant be 20.1/min? (R = 8.314 J/mol • K)

Answer 1

Use the Arrhenius equation:

ln (k2/k1) = -Ea/R (1/T2 - 1T1)

k1 = 24.5/min

k2 = 20.1/min

Ea = 13.6 kJ/mol

R = 8.314 J/Kmol = 0.008314 kJ/Kmol

T1 = 754ºC + 273 = 1027K

T2 = ?

ln (20.1/24.5) = -13.6/0.008314 (1/T2 - 1/1027)

-0.198 = -1636 (1/T2 - 0.000974)

-0.198 = -1636/T2 + 1.59

-1.79 = -1636/T2

T2 = 914K

T2 = 914K - 273 = 641ºC