The reaction C4H8(g)⟶2C2H4(g) has an activation energy of 262 kJ/mol. At 600.0 K, the rate constant, 𝑘, is 6.1×10−8 s−1. What is the value of the rate constant at 835.0 K?

Answer 1

Use the Arrhenius equation:

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

k1 = 6.1x10^-8s^-1

k2 = ?

Ea = 262 kJ/mol

R = 0.008314 kJ/K-mol (note to change units of R to kJ instead of J)

T1 = 600K

T2 = 835K

ln(k2) - ln 6.1x10^-8 = -262/0.008314 (1/835 - 1/600)

ln k2 - (-16.6) = -31,513 ( -0.00000067)

ln k2 + 16.6 = 0.021

ln K2 = -16.58

k2 = 6.30x10^-8

(Please be sure to check the math)