Question

Arhenius equation is not applicable for :

• A. first order reactions
• B. second order reactions
• C. zero order reaction
• D. radioactive decay

Answer 1

The correct option is D radioactive decay

Arrhenius equation describes the effect of temperature on the velocity of a chemical reaction, the basis of all predictive expressions used for calculating reaction-rate constants. In the Arrhenius equation, k is the reaction rate constant, A and E are numerical constants characteristic of the reacting substances, R is the thermodynamic gas constant, and T is the absolute temperature.

Arrhenius equation is $k=A{e}^{-E_a/RT}$. Arrhenius equation is concerned with the temperature dependence of rates of chemical reactions.

Radioactive decay is not a chemical reaction. It is a nuclear phenomenon resulting from the instability of the nucleus of an atom. Also, radioactivity is generally unaffected by temperature change and so, Arrhenius equation is not applicable.