Choose the incorrect statement:

The correct answer is Option (4) → Rate of reaction decreases with rise in temperature.

Reactant molecules must pass through a high-energy activated complex before they become products; the energy needed to reach it is the activation energy (E_a). A rise in temperature increases the fraction of molecules with energy equal to or greater than E_a, so the rate constant increases (Arrhenius equation, \( k = A\,e^{-E_a/RT} \)). For many reactions a rise of 10° nearly doubles the rate constant.

• Option (1) In endothermic reaction reactant molecules have lower energy than product molecules — A correct statement. Heat is absorbed, so the products lie higher in energy than the reactants (ΔH > 0).

• Option (2) Energy of activated complex is higher than the energy of reactants — A correct statement. The activated complex sits at the top of the energy barrier; the difference is E_a.

• Option (3) Energy of activation of reaction is different from energy of activation with catalyst for the same reaction. — A correct statement. A catalyst provides an alternate pathway with a lower activation energy, so E_a with the catalyst is lower than E_a of the uncatalysed reaction.

• Option (4) Rate of reaction decreases with rise in temperature. — The incorrect statement. The rate increases with a rise in temperature, because more molecules can cross the energy barrier.

NCERT (2026-27 edition):
Temperature Dependence of the Rate of a Reaction

Note: The same/similar question has been asked in different years by NTA as per the details given below: