Molar Volume of Gases — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Molar Volume of Gases.

Stoichiometry with Limiting Reactant at STP

high

NEET frequently combines mole concept with stoichiometry and limiting reactants. A question could involve a reaction with gaseous reactants/products, where students need to identify the limiting reactant based on given volumes at STP, and then calculate the volume of product formed or excess reactant remaining. This tests multiple concepts in one problem, making it a good discriminator. For example, 'X liters of A reacts with Y liters of B at STP. What is the volume of product C formed at STP?'

Molar Mass Determination from Density at Non-STP Conditions

medium

This angle combines the ideal gas law, molar volume concept, and density calculations. Students would be given the density of an unknown gas at a specific temperature and pressure (not STP/NTP) and asked to find its molar mass. This requires using the formula $ ho = PM/RT$ and careful unit conversion, especially for temperature to Kelvin. It's a slightly more challenging numerical problem than direct STP calculations.

Conceptual Comparison of Molar Volumes (Ideal vs. Real Gas)

high

NEET often includes conceptual questions to test deeper understanding beyond rote memorization. A question might ask to compare the molar volume of an ideal gas with a specific real gas (e.g., $ ext{CO}_2$ or $ ext{NH}_3$) under certain conditions (e.g., high pressure, low temperature) and explain the deviation. This tests the understanding of ideal gas assumptions and the factors causing real gas deviations (intermolecular forces, molecular volume).