The correct order of molar heat capacities measured at 298 K and 1 bar is :

Bromine(l) > Copper(s) > Helium(g)

Copper(s) $>$ Bromine(l) $>$ Helium(g)

Helium(g) > Bromine(l) > Copper(s)

Helium(g) > Bromine(l) = Copper(s)

Gas 'A' undergoes change from state 'X' to state 'Y'. In this process, the heat absorbed and work done by the gas is 10 J and 18 J respectively. Now gas is brought back to state 'X' by another process during which 6 J of heat is evolved. In the reverse process of 'Y' to 'X',

14 J of the work is done on the gas 'A' by the surroundings.

18 J of the work is done by the gas 'A'.

2 J of the work is done by the gas 'A'.

12 J of the work is done on the gas 'A' by the surrounding.

Given below are two statements : Statement I : For an ideal gas, heat capacity at constant volume is always less than the heat capacity at constant pressure. Statement II : In a constant volume process, no work is produced and all the heat withdrawn goes into the chaotic motion and is reflected by a temperature increase of the ideal gas. In the light of the above statements, choose the correct answer from the options given below

Statement I is false but Statement II is true

Both Statement I and Statement II are true

Both Statement I and Statement II are false

Statement I is true but Statement II is false

Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at the boiling point of water. Choose the correct option.

Both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are (+ve)

Both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are (-ve)

$\Delta \mathrm{H}$ is $(+\mathrm{ve})$ but $\Delta \mathrm{S}$ is (-ve)

$\Delta \mathrm{H}$ is $(-\mathrm{ve})$ but $\Delta \mathrm{S}$ is (+ve)

Thermodynamics — JEE Main Previous Year Questions

202 solved PYQs · 2016–2026 · Chemistry

Solved PYQs: 202
Years covered: 2016–2026
Avg / year: ~18
Subject: Chemistry

How many JEE Main questions come from Thermodynamics?

Thermodynamics has contributed 202 questions to Joint Entrance Examination (Main) papers between 2016 and 2026 — an average of about 18 questions a year. That count is measured from EByAi’s bank of 55,289 JEE Main questions, not estimated from a syllabus. Every one of the 202 questions carries a written, step-by-step solution, and each is tagged to Thermodynamics within Chemistry, so you can drill this chapter across every year at once instead of hunting through paper PDFs. Practising a chapter’s full PYQ history is the fastest way to learn the patterns examiners reuse.

Sample Thermodynamics questions from real JEE Main papers

These are 5 real questions from the bank — exactly as asked, with the answer one tap away. All 202 Thermodynamics questions (with full written solutions) are available in practice.

Question 1 · JEE Main 2026
The correct order of molar heat capacities measured at 298 K and 1 bar is :
1. (A) $Copper(s) > Bromine(l) > Helium(g)$
2. (B) $Bromine(l) > Copper(s) > Helium(g)$
3. (C) $Helium(g) > Bromine(l) > Copper(s)$
4. (D) $Helium(g) > Bromine(l) = Copper(s)$
Show answerAnswer
$Answer: (B) Bromine(l) > Copper(s) > Helium(g)$
Question 2 · JEE Main 2026
Gas 'A' undergoes change from state 'X' to state 'Y'. In this process, the heat absorbed and work done by the gas is 10 J and 18 J respectively. Now gas is brought back to state 'X' by another process during which 6 J of heat is evolved. In the reverse process of 'Y' to 'X',
1. (A) $18 J of the work is done by the gas 'A'.$
2. (B) $2 J of the work is done by the gas 'A'.$
3. (C) $12 J of the work is done on the gas 'A' by the surrounding.$
4. (D) $14 J of the work is done on the gas 'A' by the surroundings.$
Show answerAnswer
$Answer: (D) 14 J of the work is done on the gas 'A' by the surroundings.$
Question 3 · JEE Main 2026
Given below are two statements : Statement I : For an ideal gas, heat capacity at constant volume is always less than the heat capacity at constant pressure. Statement II : In a constant volume process, no work is produced and all the heat withdrawn goes into the chaotic motion and is reflected by a temperature increase of the ideal gas. In the light of the above statements, choose the correct answer from the options given below
1. (A) $Both Statement I and Statement II are true$
2. (B) $Both Statement I and Statement II are false$
3. (C) $Statement I is true but Statement II is false$
4. (D) $Statement I is false but Statement II is true$
Show answerAnswer
$Answer: (D) Statement I is false but Statement II is true$
Question 4 · JEE Main 2025
500 J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm. The final temperature and the change in internal energy respectively are: Given: R = 8.3 J K -1 mol -1
1. (A) $368 K and 500 J$
2. (B) $348 K and 300 J$
3. (C) $378 K and 300 J$
4. (D) $378 K and 500 J$
Show answerAnswer
$Answer: (B) 348 K and 300 J$
Question 5 · JEE Main 2025
Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at the boiling point of water. Choose the correct option.
1. (A) $Both Δ H and Δ S are (-ve)$
2. (B) $Δ H is (+ ve) but Δ S is (-ve)$
3. (C) $Δ H is (- ve) but Δ S is (+ve)$
4. (D) $Both Δ H and Δ S are (+ve)$
Show answerAnswer
$Answer: (D) Both Δ H and Δ S are (+ve)$

Thermodynamics questions by year

Year	Questions	Share of chapter questions
2026	22
2025	31
2024	22
2023	25
2022	23
2021	24
2020	14
2019	22
2018	8
2017	6
2016	5

Practise these 202 questions with solutions

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FAQs

How many JEE Main questions have been asked from Thermodynamics?

EByAi's bank holds 202 real JEE Main questions from Thermodynamics, asked between 2016 and 2026 — about 18 per year on average. Every count is measured from actual papers, not estimated.

Is Thermodynamics important for JEE Main?

202 questions over 11 papers make Thermodynamics a high-weightage chapter in JEE Main Chemistry. The year-wise table above shows exactly how often it appears.

Can I solve Thermodynamics PYQs online for free?

Yes. EByAi lets you solve JEE Main past-year questions in the browser with written solutions — free daily practice, no card needed.

More JEE Main Chemistry chapters

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