Activation Energy

The decomposition of NO₂ follows a second order rate equation. Data at different temperatures are as follows:

T (K)		592	603	627	651.5	656
k (cm3/gmol.sec)  522	755	1700	4020	5030

Compute the energy of activation Energy from the data. The reaction is 2NO₂ → 2NO + O₂

Calculations:

Activation energy is found from the Arrhenius' relation

k = k_o e^-E/RT

i.e.,

ln k vs. 1/T is a straight line with a slope of -E/R

where, E is the activation energy; and

R is the universal gas constant.

From the above data, the following graph is drawn, and the slope is = -13622

Therefore,

E/R = 13622

E = 13622 x 8314 = 113253.3 kJ/kmol