Chemical Thermodynamics JEE Main PYQs PDF, 2020–2026

Chemical Thermodynamics questions per year

in the free PDF asked, not in the PDFThe PDF only has questions we can print in full with a checked answer, so it holds 161 of the 163 asked.

Topic-wise weightage by year

How many Chemical Thermodynamics questions each topic had in every JEE Main year (all shifts), counting every question asked, including ones not in the PDF. Darker cells mean more questions.

Swipe the table sideways for older years.

Newest questions (2026)

The 12 newest of the 22 JEE Main 2026 Chemical Thermodynamics questions in the free PDF, latest shift first.

1. JEE Main 2026 · 8 Apr · Shift 2 · Hess's Law

   Consider the reaction

   $2{\mathrm{H}}_{2}{\ \mathrm{S}}({\ \mathrm{g}})+3{\mathrm{O}}_{2}({\ \mathrm{g}})\rightarrow 2{\mathrm{H}}_{2}{\mathrm{O}}({\mathrm{l}})+2{\mathrm{SO}}_{2}({\ \mathrm{g}})$

   The magnitude of enthalpy change for the reaction in ${\mathrm{kJ}}{\mathrm{mol}}^{{-1}}$ is $\_\_\_\_$ . (Nearest integer)

   $\begin{array}{cc}Given:\quad & \Delta_{{{\mathrm{f}}}}{\mathrm{H}}^{{\ominus}}({\mathrm{H}}_{2}{\ \mathrm{S}})=-20.1{\ \mathrm{kJ}}{\ \mathrm{mol}}^{{-1}} \\ & \Delta_{{{\mathrm{f}}}}{\mathrm{H}}^{{\ominus}}({\mathrm{H}}_{2}{\mathrm{O}})=-286.0{\ \mathrm{kJ}}{\ \mathrm{mol}}^{{-1}} \\ & \Delta_{{{\mathrm{f}}}}{\mathrm{H}}^{{\ominus}}({\mathrm{SO}}_{2})=-297.0{\ \mathrm{kJ}}{\ \mathrm{mol}}^{{-1}}\end{array}$

   Solve it online →

2. JEE Main 2026 · 6 Apr · Shift 1 · Gibbs Free Energy

   Consider the reaction ${\mathrm{X}}\rightleftharpoons {\mathrm{Y}}$ at 300 K . If $\Delta{\mathrm{H}}^{\theta}$ and K are $28.40{\ \mathrm{kJ}}{\ \mathrm{mol}}^{{-1}}$ and $1.8\times {10}^{{-7}}$ at the same temperature, then the magnitude of $\Delta{\mathrm{S}}^{\theta}$ for the reaction in ${\mathrm{JK}}^{{-1}}{\ \mathrm{mol}}^{{-1}}$ is $\_\_\_\_$ . (Nearest integer)

   (Given : ${\mathrm{R}}=8.3{\ \mathrm{J}}{\ \mathrm{K}}^{{-1}}{\ \mathrm{mol}}^{{-1}},\ln 10=2.3,\log 3=0.48,\log 2=0.30$ )

   Solve it online →

3. JEE Main 2026 · 6 Apr · Shift 1 · First Law and Internal Energy

   Arrange the following isothermal processes in order of the magnitude of the work $({\mathrm{p}}-{\mathrm{V}})$ involved between states 1 and 2.

   A. Expansion in single stage ${\mathrm{w}}_{{{\mathrm{A}}}}$

   B. Expansion in multi stages $w_{B}$

   C. Compression in single stage ${\mathrm{w}}_{{{\mathrm{C}}}}$

   D. Compression in multi stages $w_{D}$

   Choose the correct option.

   Solve it online →

4. JEE Main 2026 · 6 Apr · Shift 2 · First Law and Internal Energy

   Match List - I with List - II.

   Given $V_{1}$ and $V_{2}$ are initial and final volumes respectively.

   List - I (Isothermal process)		List - II (Expression)
   A.	Reversible expansion	I.	${\mathrm{q}}=0$
   B.	Free expansion	II.	${\mathrm{q}}={\mathrm{nRT}}\ln \frac{{\ \mathrm{V}}_{2}}{{\ \mathrm{V}}_{1}}$
   C.	Irreversible Compression	III.	${\mathrm{w}}=-{\mathrm{p}}_{{{\mathrm{ext}}}}({\ \mathrm{V}}_{1}-{\mathrm{V}}_{2})$
   D.	Cyclic reversible	IV.	$\frac{{\mathrm{q}}_{{{\mathrm{rev}}}}}{{\ \mathrm{T}}}=0$

   Choose the correct answer from the options given below :

   Solve it online →

5. JEE Main 2026 · 5 Apr · Shift 2 · Enthalpy and Heat Capacity

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

   Solve it online →

6. JEE Main 2026 · 5 Apr · Shift 2 · Gibbs Free Energy

   Consider the following data for the reaction

   $X_{2}(g)+Y_{2}(g)\rightleftharpoons 2XY(g)$

   at $600{\ \mathrm{K}}^{{\circ}}$. The $\Delta_{{{\mathrm{r}}}}{\mathrm{G}}^{{\ominus}}$ (in ${\mathrm{kJ}}{\mathrm{mol}}^{{-1}}$ ) for the reaction is :

   $\begin{array}{ccc}\text{ Compound} & \Delta_{f}{\mathrm{H}}_{{600{\ \mathrm{K}}}}^{{\ominus}}\left({\mathrm{kJ}}{\ \mathrm{mol}}^{{-1}}\right) & {\mathrm{S}}^{{\ominus}}{}_{{600{\ \mathrm{K}}}}\left({\ \mathrm{J}}{\ \mathrm{mol}}^{{-1}}{\ \mathrm{K}}^{{-1}}\right) \\ {\mathrm{XY}}({\ \mathrm{g}}) & 42 & 200 \\ {\mathrm{X}}_{2}({\ \mathrm{g}}) & 8 & 140 \\ {\mathrm{Y}}_{2}({\ \mathrm{g}}) & 80 & 250\end{array}$

   Solve it online →

7. JEE Main 2026 · 4 Apr · Shift 2 · Hess's Law

   If 3.365 g of ethanol $({\mathrm{l}})$ is burnt completely in a bomb calorimeter at 298.15 K , the heat produced is 99.472 kJ . The $|\Delta{\mathrm{H}}_{{{\mathrm{f}}}}{}^{{\circ}}|$ of ethanol at 298.15 K is

   $\_\_\_\_$ $\times {10}^{2}{\ \mathrm{kJ}}{\ \mathrm{mol}}^{{-1}}$. (Nearest integer)

   Given: Standard enthalpy for combustion of graphite $=-393.5{\ \mathrm{kJ}}{\ \mathrm{mol}}^{{-1}}$

   Standard enthalpy of formation of water $({\mathrm{l}})=-285.8{\ \mathrm{kJ}}{\ \mathrm{mol}}^{{-1}}$

   Molar mass in ${\mathrm{g}}{\mathrm{mol}}^{{-1}}$ of ${\mathrm{C}},{\mathrm{H}},{\mathrm{O}}$ are 12,1 and 16 respectively

   Solve it online →

8. JEE Main 2026 · 4 Apr · Shift 1 · First Law and Internal Energy

   Given below are two statements :

   Statement I : For an ideal gas, heat capacity at constant volume is always greater 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

   Solve it online →

9. JEE Main 2026 · 2 Apr · Shift 1 · Hess's Law

   Consider the following data.

   (i) $2\text{Al(s)}+6\text{HCl(aq)}\rightarrow \text{Al}_{2}\text{Cl}_{6}\text{(aq)}+3\text{H}_{2}\text{(g)}+1200\ \text{kJ/mol}$

   (ii) $\text{H}_{2}\text{(g)}+\text{Cl}_{2}\text{(g)}\rightarrow 2\text{HCl(g)}+164\ \text{kJ/mol}$

   (iii) $\text{HCl(g)}+\text{aq}\rightarrow \text{HCl(aq)}+83\ \text{kJ/mol}$

   (iv) $\text{Al}_{2}\text{Cl}_{6}\text{(s)}+\text{aq}\rightarrow \text{Al}_{2}\text{Cl}_{6}\text{(aq)}+663\ \text{kJ/mol}$

   The enthalpy of formation of anhydrous solid $\text{Al}_{2}\text{Cl}_{6}$ is :

   Solve it online →

10. JEE Main 2026 · 2 Apr · Shift 2 · First Law and Internal Energy

    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',

    Solve it online →

11. JEE Main 2026 · 2 Apr · Shift 1 · Gibbs Free Energy

    At the transition temperature $T$, $A\rightleftharpoons B$ and $\Delta G^{0}=105-35\log T$ where A and B are two states of substance X. The transition temperature in ${}^{{\circ}}{\mathrm{C}}$ when pressure is 1 atm is ________. (Nearest integer)

    Solve it online →

12. JEE Main 2026 · 28 Jan · Shift 1 · First Law and Internal Energy

    $20.0{\mathrm{dm}}^{3}$ of an ideal gas ' X ' at 600 K and 0.5 MPa undergoes isothermal reversible expansion until pressure of the gas is 0.2 MPa . Which of the following option is correct?

    (Given: $\log 2=0.3010$ and $\log 5=0.6989$ )

    Solve it online →

Practise the 2026 Chemical Thermodynamics questions online

Sample questions from recent papers

The free PDF above has all 161 questions grouped by topic, with an answer key.

Frequently asked

More Chemistry chapters

• Alcohols, Phenols & Ethers (108 asked · 65 in PDF)
• Aldehydes & Ketones (126 asked · 70 in PDF)
• Amines & Diazonium Salts (167 asked · 154 in PDF)
• Atomic Structure (170 asked · 169 in PDF)
• Carbohydrates & Biomolecules (154 asked · 141 in PDF)
• Carboxylic Acids & Their Derivatives (32 asked · 21 in PDF)
• Chemical Bonding & Molecular Structure (207 asked · 203 in PDF)
• Chemical Equilibrium (85 asked · 81 in PDF)
• Chemical Kinetics (151 asked · 147 in PDF)
• Chemistry in Everyday Life (58 asked · 53 in PDF)
• Coordination Compounds (248 asked · 244 in PDF)
• d & f Block Elements (173 asked · 169 in PDF)
• Electrochemistry (167 asked · 165 in PDF)
• Environmental Chemistry (82 asked · 16 in PDF)
• General Organic Chemistry (GOC) (176 asked · 156 in PDF)
• Halogen Derivatives: Haloalkanes & Haloarenes (123 asked · 69 in PDF)
• Hydrocarbons: Alkanes (35 asked · 29 in PDF)
• Hydrocarbons: Alkenes & Alkynes (89 asked · 45 in PDF)
• Hydrocarbons: Aromatic (Arenes) (81 asked · 51 in PDF)
• Hydrogen & s-Block Elements (134 asked · all in PDF)
• Ionic Equilibrium (99 asked · 96 in PDF)
• Metallurgy (84 asked · all in PDF)
• Mole Concept & Stoichiometry (206 asked · 201 in PDF)
• Nuclear & Radiochemistry (10 asked · all in PDF)
• p-Block Elements: Part I (Group 13 & 14) (57 asked · all in PDF)
• p-Block Elements: Part II (Group 15-18) (105 asked · 103 in PDF)
• Periodic Table & Periodicity (124 asked · 122 in PDF)
• Polymers (52 asked · 46 in PDF)
• Practical Organic Chemistry (37 asked · 35 in PDF)
• Purification & Characterisation of Organic Compounds (128 asked · 123 in PDF)
• Qualitative Analysis: Salt Analysis (78 asked · 77 in PDF)
• Redox Reactions (87 asked · 86 in PDF)
• Solid State (44 asked · all in PDF)
• Solutions & Colligative Properties (153 asked · 150 in PDF)
• Surface Chemistry (82 asked · all in PDF)

JEE Main PYQs by year: 2026 · 2025 · 2024 · 2023 · 2022 · 2021 · 2020