Arrhenius Equation — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Arrhenius Equation.

Combined effect of catalyst and temperature change

high

NEET often tests integrated concepts. A question might involve a reaction whose rate constant is known at one temperature, then a catalyst is added (changing $E_a$), and the new rate constant is asked at a different temperature. This requires applying the Arrhenius equation twice or using the ratio form, considering the change in $E_a$ due to the catalyst. Such problems test both numerical proficiency and conceptual understanding of catalysts' role.

Graphical interpretation with non-standard plots

medium

While $ln k$ vs $1/T$ is standard, questions might present plots like $log_{10} k$ vs $1/T$ or even $k$ vs $T$ (requiring recognition of its non-linearity). Students would need to know the relationship between $ln$ and $log_{10}$ ($ln x = 2.303 log_{10} x$) and adjust the slope interpretation accordingly ($-rac{E_a}{2.303R}$ for $log_{10} k$ plot). This tests a deeper understanding of logarithmic properties and the Arrhenius equation's derivations.

Impact of $E_a$ on temperature sensitivity

medium

A conceptual question could ask which of two reactions (with different $E_a$ values) would be more sensitive to a given temperature change. Reactions with higher activation energies are generally more sensitive to temperature changes because the exponential term $e^{-E_a/RT}$ changes more drastically for larger $E_a$ values with a small change in $T$. This tests the qualitative understanding of the exponential dependence.