According to the Arrhenius equation, a straight line is to be obtained by plotting the logarithm of the rate constant of a chemical reaction $\left(\log \mathrm{ }\mathrm{k}\right)$ against:

For an endothermic reaction where $∆\mathrm{H}$ represents the enthalpy of reaction in $\mathrm{kJ}/\mathrm{mol}$, the minimum value for the energy of activation will be:

For the decomposition of ${\mathrm{N}}_2{\mathrm{O}}_5( \mathrm{g})$ it is given that- 

$2 {\mathrm{N}}_2{\mathrm{O}}_5( \mathrm{g})\to 4{\mathrm{NO}}_2( \mathrm{g})+{\mathrm{O}}_2( \mathrm{g})$ 

activation energy $=\mathrm{Ea}$

${\mathrm{N}}_2{\mathrm{O}}_5( \mathrm{g})\to 2{\mathrm{NO}}_2( \mathrm{g})+\frac{1}{2}{\mathrm{O}}_2( \mathrm{g})$

activation energy $= \mathrm{Ea}\text{'}$ then