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 870.0 K?

Question

Please help me with this question!

Answer 1

To solve this problem, you need to be familiar with the Arrhenius equation, which is...

k = Ae^-Ea/RT

There is also a manipulation of this formula which gives you...

ln k₂ = ln k₁ - (E_a/R)(1/T₂ - 1/T₁)

When you plug in your known values, you get...

ln k₂ = ln 6.1E-8 - (2.62E5/R)(1/870 - 1/600) [NOTE: E_a has been converted to joules since the gas constant has joules in its units rather than kJ]

When you plug the right side of the equation into a calculator, you get...

ln k₂ = -0.31

When you take e to the power of each side, you get...

k₂ = 0.73