Question

For an endothermic reaction, $\Delta$H represents the enthalpy of the reaction in $kJ mol^{-1}$. The minimum amount of activation energy will be

• A. less than zero
• B. equal to $\Delta H$
• C. less than $\Delta H$
• D. more than $\Delta H.$

Answer 1

Answer: (D)

For a reaction, $E_{ a _{ pr }}=\Delta H+E_{ a _{ BR }}$. For endothermic reaction, $\Delta H=$ positive; thus $E_{ a _{ FR }}>\Delta H$
For exothermic reaction, $\Delta H=$ negative, thus nothing can be said.