Calculate the rate constant, 𝑘 , for a reaction at 50.0 °C that has an activation energy of 86.2 kJ/mol and a frequency factor of 3.46×1011 s−1.

Answer 1

The Arrhenius equation can be used to approximate the rate constant at different temperatures:

rate = A e^(-Ea/RT)

where A is the frequency factor, Ea is the activation energy, and R is the gas constant (8.314 J/mol/k).

If we plug in the values from the problem, making sure we convert to the correct units we get:

rate = 3.46x10¹¹ * e^{(-86,200/8.314/323)}

(note that the Ea was converted from kJ/mol to J/mol, and the temperature was converted from C to K)

Solving this equation we get:

rate = 0.0040 s^-1