Chemical Thermodynamics CBSE Class 11 MCQ & Practice Questions

Practice Chemical Thermodynamics MCQs for CBSE Class 11 Chemistry with answers, explanations, chapter revision and related ChemNexa mock tests.

Chemical Thermodynamics Revision Guide for CBSE Class 11 Chemistry

Thermodynamics relates heat, work, internal energy, enthalpy and spontaneity. It is best learned through sign conventions and state-function logic rather than isolated memorisation.

For CBSE Class 11 Chemistry, revise the first law, enthalpy changes, Hess law, entropy and Gibbs free energy, then practise conceptual and numerical MCQs together.

Important Topics

System, surroundings and state functions
First law of thermodynamics
Enthalpy and heat capacity
Hess law
Entropy
Gibbs free energy and spontaneity

Important Formulae & Relationships

ΔU = q + w
At constant pressure: qp = ΔH
ΔH = ΔU + ΔngRT (for ideal-gas reactions)
ΔG = ΔH − TΔS
ΔG° = −RT ln K

Use formulas only after checking the required units, sign convention and assumptions for the question.

What to practise in Chemical Thermodynamics

Concept Revision

Revise definitions, principles, equations, trends and core ideas from Chemical Thermodynamics before attempting MCQs.

Exam-style MCQs

Use chapter-focused multiple-choice practice to improve accuracy, recall and application for CBSE Class 11 Chemistry.

Performance Practice

Attempt ChemNexa tests, review results and return to weak areas for another round of targeted revision.

Top 7 Chemical Thermodynamics MCQs with Answers

These public questions are selected from the exact Chemical Thermodynamics chapter, screened for topic relevance and deduplicated so repeated versions of the same MCQ are not shown publicly. Use them for quick revision, then sign in to attempt the complete test experience with more questions, results and performance review.

CBSE Class 11 Chemistry · Chemical Thermodynamics · Medium

1. A process is spontaneous at constant temperature and pressure when ΔG is:

A. Positive
B. Negative
C. Zero only
D. Equal to ΔH

Answer: B

Explanation: Spontaneity is indicated by a negative Gibbs energy change.

CBSE Class 11 Chemistry · Chemical Thermodynamics · Very Hard

2. At 298 K, ΔH = −40 kJ mol⁻¹ and ΔS = −100 J K⁻¹ mol⁻¹. ΔG is:

A. −69.8 kJ mol⁻¹
B. −10.2 kJ mol⁻¹
C. +10.2 kJ mol⁻¹
D. +69.8 kJ mol⁻¹

Answer: B

Explanation: ΔG=ΔH−TΔS=−40−298(−0.100)=−10.2 kJ mol⁻¹.

CBSE Class 11 Chemistry · Chemical Thermodynamics · Medium

3. For an exothermic reaction, ΔH is:

A. Positive
B. Negative
C. Zero always
D. Equal to ΔG

Answer: B

Explanation: Heat is released, so enthalpy of products is lower than that of reactants.

CBSE Class 11 Chemistry · Chemical Thermodynamics · Very Hard

4. If ΔHf°[CO₂(g)] = −393.5 kJ mol⁻¹ and ΔHf°[H₂O(l)] = −285.8 kJ mol⁻¹, ΔH° for CH₄ + 2O₂ → CO₂ + 2H₂O is −890.3 kJ mol⁻¹. ΔHf°[CH₄(g)] is:

A. −74.8 kJ mol⁻¹
B. +74.8 kJ mol⁻¹
C. −965.1 kJ mol⁻¹
D. +965.1 kJ mol⁻¹

Answer: A

Explanation: −890.3=[−393.5+2(−285.8)]−ΔHf(CH₄), so ΔHf(CH₄)=−74.8.

CBSE Class 11 Chemistry · Chemical Thermodynamics · Medium

5. Hess law is based on the fact that enthalpy is a:

A. Path function
B. State function
C. Intensive property only
D. Kinetic property

Answer: B

Explanation: Enthalpy change depends only on initial and final states.

CBSE Class 11 Chemistry · Chemical Thermodynamics · Very Hard

6. Which change has the greatest positive entropy change?

A. H₂O(l) → H₂O(s)
B. H₂O(l) → H₂O(g)
C. N₂(g) → N₂(l)
D. NaCl(aq) → NaCl(s)

Answer: B

Explanation: Vaporisation produces much greater molecular freedom.

CBSE Class 11 Chemistry · Chemical Thermodynamics · Medium

7. Entropy is a measure of:

A. Heat content
B. Randomness or disorder
C. Activation energy
D. Bond order

Answer: B

Explanation: Entropy quantifies dispersal of energy and molecular disorder.

Chemical Thermodynamics Practice Tests