The activation energy for the reaction 2 HI(g) → H₂ + I₂ (g) is 209.5 kJ mol^–¹ at 581K.Calculate the fraction of molecules of reactants having energy equal to or greater than activation energy?

Question

Philoid · Accepted Answer

Given-

Energy of activation, E_a= 209.5 kJ mol^–¹

E_a in joules = 209.5 × 1000 = 209500 J mol^–¹

Temperature, T = 581K

Gas constant, R = 8.314 J K^-1 mol^-1

Using Arrhenius equation,

k = A

In this equation, the term represents the number of molecules which have kinetic energy greater than the activation energy, E_a.

∴ The number of molecules = → Equation 1

Substituting all the known values in equation 1, we get,

⇒

= e^-43.3708

Finding the value of anti ln(43.3708), we get, 1.47 × 10^-19

The fraction of molecules of reactants having energy equal to or greater than activation energy is 1.47 × 10^-19

The activation energy for the reaction 2 HI(g) → H2 + I2 (g) is 209.5 kJ mol–1 at 581K.Calculate the fraction of molecules of reactants having energy equal to or greater than activation energy?