Skip to main content
ExamCompass
Exam Compass LogoExamCompass
BlogFounderAppLogin

Exams

JEE Main & AdvancedNEET UGClass 12 BoardsClass 11 Boards

Categories

All ArticlesExam NotesRevision
Meet the FounderDownload Android & iOS AppLogin
Home/JEE MAINS/chemistry/thermodynamics
Curated PYQ Collection

Top 50 Most Repeated THERMODYNAMICS PYQs | JEE MAINS

A curated collection of the most important questions from THERMODYNAMICS, fully solved with step-by-step concepts to prepare for JEE MAINS.

Question #1

Practice Question

Concept Applied

Use Hess's law: $\Delta H = [\Delta H_f(CO_2)] - [2\times\Delta H_f(CO)] = -393.5 - 2(-110.5) = -172.5$ kJ....

Read Full Step-by-Step Solution →

Question #2

Practice Question

Concept Applied

ΔG° = ΔH° − TΔS° = 30000 − 298×40 = 18080 J/mol ≈ 18 kJ/mol....

Read Full Step-by-Step Solution →

Question #3

Practice Question

A.Work
B.Heat
C.Internal Energy
D.Power

Concept Applied

State functions depend only on initial and final states. Internal energy is a state function....

Read Full Step-by-Step Solution →

Question #4

Practice Question

A.Yes, $\Delta G < 0$
B.No, $\Delta G > 0$
C.At equilibrium, $\Delta G = 0$
D.Cannot be predicted

Concept Applied

$\Delta G = \Delta H - T\Delta S = 50 - 298 \times 0.15 = 50 - 44.7 = 5.3 > 0$ → non-spontaneous....

Read Full Step-by-Step Solution →

Question #5

Practice Question

A.Non-spontaneous
B.Spontaneous
C.At equilibrium
D.Reversible

Concept Applied

$\Delta G^\circ < 0$ implies spontaneous under standard conditions....

Read Full Step-by-Step Solution →

Question #6

Practice Question

Concept Applied

Using the first law of thermodynamics, ΔU = q + w. Heat absorbed by the system is +500 kJ. Work done by the system is taken as –200 kJ. Hence, ΔU = 50...

Read Full Step-by-Step Solution →

Question #7

Practice Question

A.$6.0 \times 10^{5}$
B.
.2 \times 10^{5}$
C.$3.0 \times 10^{4}$
D.$5.0 \times 10^{2}$

Concept Applied

Using $\Delta G^{\circ} = -RT\ln K$, we have $\ln K = -\Delta G^{\circ}/(RT) = 33000/(8.314\times298) \approx 13.33$, so $K = e^{13.33} \approx 6.0\ti...

Read Full Step-by-Step Solution →

Question #8

Practice Question

A.-33.4 kJ mol⁻¹
B.-92.4 kJ mol⁻¹
C.-59.0 kJ mol⁻¹
D.+33.4 kJ mol⁻¹

Concept Applied

ΔG° = ΔH° – TΔS°. Convert ΔS° to kJ K⁻¹ (–0.198 kJ K⁻¹). Then ΔG° = –92.4 kJ – (298 K)(–0.198 kJ K⁻¹) = –92.4 kJ + 59.0 kJ = –33.4 kJ. The negative si...

Read Full Step-by-Step Solution →

Question #9

Practice Question

A.ΔH₃ = +679.3 kJ/mol
B.ΔH₃ = -679.3 kJ/mol
C.ΔH₃ = +108.7 kJ/mol
D.ΔH₃ = -108.7 kJ/mol

Concept Applied

Reverse reaction (1) and (2) to obtain reactants on the right. ΔH for reversed steps changes sign. Adding the reversed ΔH values gives ΔH₃ = (+393.5) ...

Read Full Step-by-Step Solution →

Question #10

Practice Question

A.180.2 kJ mol⁻¹
B.182.0 kJ mol⁻¹
C.179.0 kJ mol⁻¹
D.185.5 kJ mol⁻¹

Concept Applied

First compute ΔCₚ = ΣνCₚ(products) – ΣνCₚ(reactants) = (2·(29.9+0.012T)) – [(29.1+0.01T)+(29.4+0.015T)] = 1.3 – 0.001T. Integrate ΔCₚ from 298 K to 50...

Read Full Step-by-Step Solution →

Question #11

Practice Question

Concept Applied

Reaction becomes spontaneous when ΔG < 0 → T > ΔH/ΔS = 60000/200 = 300 K....

Read Full Step-by-Step Solution →

Question #12

Practice Question

Concept Applied

Bond dissociation energy for 1 mol H₂ = 436 kJ; for 0.5 mol = 218 kJ....

Read Full Step-by-Step Solution →

Question #13

Practice Question

Concept Applied

Use Hess's law: $\Delta H = [\Delta H_f(CO_2)] - [2\times\Delta H_f(CO)] = -393.5 - 2(-110.5) = -172.5$ kJ....

Read Full Step-by-Step Solution →

Question #14

Practice Question

Concept Applied

ΔG° = ΔH° − TΔS° = 30000 − 298×40 = 18080 J/mol ≈ 18 kJ/mol....

Read Full Step-by-Step Solution →

Question #15

Practice Question

A.Work
B.Heat
C.Internal Energy
D.Power

Concept Applied

State functions depend only on initial and final states. Internal energy is a state function....

Read Full Step-by-Step Solution →

Question #16

Practice Question

A.Yes, $\Delta G < 0$
B.No, $\Delta G > 0$
C.At equilibrium, $\Delta G = 0$
D.Cannot be predicted

Concept Applied

$\Delta G = \Delta H - T\Delta S = 50 - 298 \times 0.15 = 50 - 44.7 = 5.3 > 0$ → non-spontaneous....

Read Full Step-by-Step Solution →

Question #17

Practice Question

A.Non-spontaneous
B.Spontaneous
C.At equilibrium
D.Reversible

Concept Applied

$\Delta G^\circ < 0$ implies spontaneous under standard conditions....

Read Full Step-by-Step Solution →

Question #18

Practice Question

Concept Applied

Using the first law of thermodynamics, ΔU = q + w. Heat absorbed by the system is +500 kJ. Work done by the system is taken as –200 kJ. Hence, ΔU = 50...

Read Full Step-by-Step Solution →

Question #19

Practice Question

A.$6.0 \times 10^{5}$
B.
.2 \times 10^{5}$
C.$3.0 \times 10^{4}$
D.$5.0 \times 10^{2}$

Concept Applied

Using $\Delta G^{\circ} = -RT\ln K$, we have $\ln K = -\Delta G^{\circ}/(RT) = 33000/(8.314\times298) \approx 13.33$, so $K = e^{13.33} \approx 6.0\ti...

Read Full Step-by-Step Solution →

Question #20

Practice Question

A.-33.4 kJ mol⁻¹
B.-92.4 kJ mol⁻¹
C.-59.0 kJ mol⁻¹
D.+33.4 kJ mol⁻¹

Concept Applied

ΔG° = ΔH° – TΔS°. Convert ΔS° to kJ K⁻¹ (–0.198 kJ K⁻¹). Then ΔG° = –92.4 kJ – (298 K)(–0.198 kJ K⁻¹) = –92.4 kJ + 59.0 kJ = –33.4 kJ. The negative si...

Read Full Step-by-Step Solution →

Question #21

Practice Question

A.ΔH₃ = +679.3 kJ/mol
B.ΔH₃ = -679.3 kJ/mol
C.ΔH₃ = +108.7 kJ/mol
D.ΔH₃ = -108.7 kJ/mol

Concept Applied

Reverse reaction (1) and (2) to obtain reactants on the right. ΔH for reversed steps changes sign. Adding the reversed ΔH values gives ΔH₃ = (+393.5) ...

Read Full Step-by-Step Solution →

Question #22

Practice Question

A.180.2 kJ mol⁻¹
B.182.0 kJ mol⁻¹
C.179.0 kJ mol⁻¹
D.185.5 kJ mol⁻¹

Concept Applied

First compute ΔCₚ = ΣνCₚ(products) – ΣνCₚ(reactants) = (2·(29.9+0.012T)) – [(29.1+0.01T)+(29.4+0.015T)] = 1.3 – 0.001T. Integrate ΔCₚ from 298 K to 50...

Read Full Step-by-Step Solution →

Question #23

Practice Question

Concept Applied

Reaction becomes spontaneous when ΔG < 0 → T > ΔH/ΔS = 60000/200 = 300 K....

Read Full Step-by-Step Solution →

Question #24

Practice Question

Concept Applied

Bond dissociation energy for 1 mol H₂ = 436 kJ; for 0.5 mol = 218 kJ....

Read Full Step-by-Step Solution →

Question #25

Practice Question

Concept Applied

Use Hess's law: $\Delta H = [\Delta H_f(CO_2)] - [2\times\Delta H_f(CO)] = -393.5 - 2(-110.5) = -172.5$ kJ....

Read Full Step-by-Step Solution →

Question #26

Practice Question

Concept Applied

ΔG° = ΔH° − TΔS° = 30000 − 298×40 = 18080 J/mol ≈ 18 kJ/mol....

Read Full Step-by-Step Solution →

Question #27

Practice Question

A.Work
B.Heat
C.Internal Energy
D.Power

Concept Applied

State functions depend only on initial and final states. Internal energy is a state function....

Read Full Step-by-Step Solution →

Question #28

Practice Question

A.Yes, $\Delta G < 0$
B.No, $\Delta G > 0$
C.At equilibrium, $\Delta G = 0$
D.Cannot be predicted

Concept Applied

$\Delta G = \Delta H - T\Delta S = 50 - 298 \times 0.15 = 50 - 44.7 = 5.3 > 0$ → non-spontaneous....

Read Full Step-by-Step Solution →

Question #29

Practice Question

A.Non-spontaneous
B.Spontaneous
C.At equilibrium
D.Reversible

Concept Applied

$\Delta G^\circ < 0$ implies spontaneous under standard conditions....

Read Full Step-by-Step Solution →

Question #30

Practice Question

Concept Applied

Using the first law of thermodynamics, ΔU = q + w. Heat absorbed by the system is +500 kJ. Work done by the system is taken as –200 kJ. Hence, ΔU = 50...

Read Full Step-by-Step Solution →

Question #31

Practice Question

A.$6.0 \times 10^{5}$
B.
.2 \times 10^{5}$
C.$3.0 \times 10^{4}$
D.$5.0 \times 10^{2}$

Concept Applied

Using $\Delta G^{\circ} = -RT\ln K$, we have $\ln K = -\Delta G^{\circ}/(RT) = 33000/(8.314\times298) \approx 13.33$, so $K = e^{13.33} \approx 6.0\ti...

Read Full Step-by-Step Solution →

Question #32

Practice Question

A.-33.4 kJ mol⁻¹
B.-92.4 kJ mol⁻¹
C.-59.0 kJ mol⁻¹
D.+33.4 kJ mol⁻¹

Concept Applied

ΔG° = ΔH° – TΔS°. Convert ΔS° to kJ K⁻¹ (–0.198 kJ K⁻¹). Then ΔG° = –92.4 kJ – (298 K)(–0.198 kJ K⁻¹) = –92.4 kJ + 59.0 kJ = –33.4 kJ. The negative si...

Read Full Step-by-Step Solution →

Question #33

Practice Question

A.ΔH₃ = +679.3 kJ/mol
B.ΔH₃ = -679.3 kJ/mol
C.ΔH₃ = +108.7 kJ/mol
D.ΔH₃ = -108.7 kJ/mol

Concept Applied

Reverse reaction (1) and (2) to obtain reactants on the right. ΔH for reversed steps changes sign. Adding the reversed ΔH values gives ΔH₃ = (+393.5) ...

Read Full Step-by-Step Solution →

Question #34

Practice Question

A.180.2 kJ mol⁻¹
B.182.0 kJ mol⁻¹
C.179.0 kJ mol⁻¹
D.185.5 kJ mol⁻¹

Concept Applied

First compute ΔCₚ = ΣνCₚ(products) – ΣνCₚ(reactants) = (2·(29.9+0.012T)) – [(29.1+0.01T)+(29.4+0.015T)] = 1.3 – 0.001T. Integrate ΔCₚ from 298 K to 50...

Read Full Step-by-Step Solution →

Question #35

Practice Question

Concept Applied

Reaction becomes spontaneous when ΔG < 0 → T > ΔH/ΔS = 60000/200 = 300 K....

Read Full Step-by-Step Solution →

Question #36

Practice Question

Concept Applied

Bond dissociation energy for 1 mol H₂ = 436 kJ; for 0.5 mol = 218 kJ....

Read Full Step-by-Step Solution →

Question #37

Practice Question

Concept Applied

Use Hess's law: $\Delta H = [\Delta H_f(CO_2)] - [2\times\Delta H_f(CO)] = -393.5 - 2(-110.5) = -172.5$ kJ....

Read Full Step-by-Step Solution →

Question #38

Practice Question

Concept Applied

ΔG° = ΔH° − TΔS° = 30000 − 298×40 = 18080 J/mol ≈ 18 kJ/mol....

Read Full Step-by-Step Solution →

Question #39

Practice Question

A.Work
B.Heat
C.Internal Energy
D.Power

Concept Applied

State functions depend only on initial and final states. Internal energy is a state function....

Read Full Step-by-Step Solution →

Question #40

Practice Question

A.Yes, $\Delta G < 0$
B.No, $\Delta G > 0$
C.At equilibrium, $\Delta G = 0$
D.Cannot be predicted

Concept Applied

$\Delta G = \Delta H - T\Delta S = 50 - 298 \times 0.15 = 50 - 44.7 = 5.3 > 0$ → non-spontaneous....

Read Full Step-by-Step Solution →

Question #41

Practice Question

A.Non-spontaneous
B.Spontaneous
C.At equilibrium
D.Reversible

Concept Applied

$\Delta G^\circ < 0$ implies spontaneous under standard conditions....

Read Full Step-by-Step Solution →

Question #42

Practice Question

Concept Applied

Using the first law of thermodynamics, ΔU = q + w. Heat absorbed by the system is +500 kJ. Work done by the system is taken as –200 kJ. Hence, ΔU = 50...

Read Full Step-by-Step Solution →

Question #43

Practice Question

A.$6.0 \times 10^{5}$
B.
.2 \times 10^{5}$
C.$3.0 \times 10^{4}$
D.$5.0 \times 10^{2}$

Concept Applied

Using $\Delta G^{\circ} = -RT\ln K$, we have $\ln K = -\Delta G^{\circ}/(RT) = 33000/(8.314\times298) \approx 13.33$, so $K = e^{13.33} \approx 6.0\ti...

Read Full Step-by-Step Solution →

Question #44

Practice Question

A.-33.4 kJ mol⁻¹
B.-92.4 kJ mol⁻¹
C.-59.0 kJ mol⁻¹
D.+33.4 kJ mol⁻¹

Concept Applied

ΔG° = ΔH° – TΔS°. Convert ΔS° to kJ K⁻¹ (–0.198 kJ K⁻¹). Then ΔG° = –92.4 kJ – (298 K)(–0.198 kJ K⁻¹) = –92.4 kJ + 59.0 kJ = –33.4 kJ. The negative si...

Read Full Step-by-Step Solution →

Question #45

Practice Question

A.ΔH₃ = +679.3 kJ/mol
B.ΔH₃ = -679.3 kJ/mol
C.ΔH₃ = +108.7 kJ/mol
D.ΔH₃ = -108.7 kJ/mol

Concept Applied

Reverse reaction (1) and (2) to obtain reactants on the right. ΔH for reversed steps changes sign. Adding the reversed ΔH values gives ΔH₃ = (+393.5) ...

Read Full Step-by-Step Solution →

Question #46

Practice Question

A.180.2 kJ mol⁻¹
B.182.0 kJ mol⁻¹
C.179.0 kJ mol⁻¹
D.185.5 kJ mol⁻¹

Concept Applied

First compute ΔCₚ = ΣνCₚ(products) – ΣνCₚ(reactants) = (2·(29.9+0.012T)) – [(29.1+0.01T)+(29.4+0.015T)] = 1.3 – 0.001T. Integrate ΔCₚ from 298 K to 50...

Read Full Step-by-Step Solution →

Question #47

Practice Question

Concept Applied

Reaction becomes spontaneous when ΔG < 0 → T > ΔH/ΔS = 60000/200 = 300 K....

Read Full Step-by-Step Solution →

Question #48

Practice Question

Concept Applied

Bond dissociation energy for 1 mol H₂ = 436 kJ; for 0.5 mol = 218 kJ....

Read Full Step-by-Step Solution →

Question #49

Practice Question

Concept Applied

Use Hess's law: $\Delta H = [\Delta H_f(CO_2)] - [2\times\Delta H_f(CO)] = -393.5 - 2(-110.5) = -172.5$ kJ....

Read Full Step-by-Step Solution →

Question #50

Practice Question

Concept Applied

ΔG° = ΔH° − TΔS° = 30000 − 298×40 = 18080 J/mol ≈ 18 kJ/mol....

Read Full Step-by-Step Solution →
ExamCompass

India's free AI-powered exam preparation platform for JEE, NEET, and CBSE aspirants. 9,000+ verified PYQs.

Competitive Exams

  • JEE Mains 2026
  • JEE Advanced 2026
  • NEET UG 2026

Board Exams

  • Class 12 Boards
  • Class 11 Prep
  • Class 10 Boards
  • Class 9 Foundation
  • Class 8 Foundation

Resources

  • Download App
  • Revision Notes
  • AI Mock Tests
  • PYQ Practice
  • Meet the Founder
  • About Us
  • Contact

Legal

  • Privacy Policy
  • Terms of Service

Exam Compass is India's free AI-powered exam preparation platform. Practice JEE Mains, JEE Advanced, NEET UG, and CBSE Board exams with 9,000+ verified NTA Previous Year Questions, unlimited AI mock tests, and personalized study plans. All free, forever.

© 2026 Exam Compass. All rights reserved.

Built with ❤️ in India by Ayush Kumar