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?

Given that
Activation energy, Ea= 209.5 kJ mol⁻¹
Multiply by 1000 to convert in j
Ea= 209500 J mol⁻¹
Temperature, T = 581 K
Gas constant, R = 8.314 JK⁻¹mol⁻¹
According to Arhenious equation
K = A e^–Ea/RT
In this formula term e^–Ea/RTrepresent the number of molecules which have energy equal or more than activation energy
Number of molecules = e^–Ea/RT
Plug the values and solving we get
Number of molecules
1.47 x 10^-19