where, ${\mathrm{E}}_{\mathrm{a}}=$ activation energy of forward reaction

${\mathrm{E}}_{\mathrm{a}}^{\text{'}}=$ activation energy of backward reaction

The above energy profile diagram shows that ${\mathrm{E}}_{\mathrm{a}}>{{\mathrm{E}}_{\mathrm{a}}}^{\text{'}}$

The potential energy of the product is greater than that of the reactant, so the reaction is endothermic.

${\mathrm{E}}_{\mathrm{a}}={\mathrm{E}}_{\mathrm{a}}^{\text{'}}+\mathrm{\Delta E}$

${\mathrm{E}}_{\mathrm{t}}={\mathrm{E}}_{\mathrm{a}}$ or ${\mathrm{E}}_{\mathrm{t}}>{{\mathrm{E}}_{\mathrm{a}}}^{\text{'}}$