Heat Capacities — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Heat Capacities.

Combined problem on First Law and Heat Capacities for a specific process

high

NEET often tests the integration of concepts. A question might provide heat supplied or work done for an isobaric or isochoric process involving an ideal gas and ask for the change in internal energy or temperature. This requires applying $Q = nC_P\Delta T$ or $Q = nC_V\Delta T$ along with $\Delta U = Q - W$. For instance, '2 moles of a diatomic gas are heated at constant pressure, absorbing $X$ Joules of heat. Find the work done by the gas.' This tests $C_P$, $C_V$, and the First Law simultaneously.

Heat capacities of gas mixtures

medium

While not as frequent as single-gas problems, questions on mixtures of ideal gases (e.g., a mixture of monoatomic and diatomic gases) are a good way to test a deeper understanding. Students would need to calculate the effective $C_V$, $C_P$, or $\gamma$ for the mixture. This involves weighted averages based on the number of moles of each gas. For example, 'A mixture contains $n_1$ moles of monoatomic gas and $n_2$ moles of diatomic gas. Find the molar heat capacity of the mixture at constant volume.'

Conceptual question on temperature dependence of heat capacities

low

While typically NEET assumes ideal gases at moderate temperatures, a conceptual question might probe the understanding that vibrational degrees of freedom become active at higher temperatures for diatomic and polyatomic gases, leading to an increase in their heat capacities. This tests a nuanced understanding beyond the basic $f=5$ for diatomic gases. For example, 'Why does the molar heat capacity of hydrogen gas increase at very high temperatures?'