Question

For an endothermic reaction where $\Delta H$ represents the enthalpy of the reaction in $kJmo{l}^{-1}$, the minimum value for the energy of activation will be.

• A. Less than
• B. Zero
• C. More than
• D. Equal to

Answer 1

The correct option is C

More than

Ea is the energy that must be possessed by the molecules in excess to the average energy at a given temperature to enter a chemical reaction. Relation between activation energy and enthalpy of a reversible reaction

If the reaction is endothermic in forward direction, then

$E_{a\left(backwards\right)}=E_{a\left(forward\right)}+\Delta H$

If the reaction is exothermic in forward direction

$E_{a\left(backward\right)}=E_{a\left(forward\right)}+\Delta H$

For an endothermic reaction, where $\Delta H$ represents the enthalpy of the reaction in $KJmo{l}^{-1}$, the minimum value for the energy of activation will be slightly more than $\Delta H$.