Physisorption and Chemisorption — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Physisorption and Chemisorption.

Comparative analysis of properties

high

The core of this topic lies in distinguishing between physisorption and chemisorption. NEET frequently tests this by asking students to identify correct/incorrect statements about their properties (e.g., reversibility, specificity, enthalpy, effect of temperature, layer formation). A question might present a scenario and ask which type of adsorption it represents, or directly ask for a contrasting feature. Mastery of the comparison table is key here.

Effect of temperature and activation energy

medium

The differential effect of temperature on physisorption (decreases with T) and chemisorption (increases then decreases with T, often requiring activation energy) is a subtle but important distinction. Questions often probe this, sometimes including the concept of activation energy specifically for chemisorption. Understanding the underlying reasons (weak forces vs. bond formation) is crucial.

Application-based questions

medium

While less frequent than direct property comparisons, NEET can ask questions that link physisorption and chemisorption to real-world applications. For example, 'Which type of adsorption is primarily involved in heterogeneous catalysis?' or 'Why is activated charcoal effective in gas masks?' These questions require not just knowing the definitions but also understanding the practical implications of their properties.