CN  ChemNexa

Thermodynamics and Thermochemistry WBJEE MCQ & Practice Questions

Practice Thermodynamics and Thermochemistry MCQs for WBJEE Chemistry with answers, explanations, chapter revision and related ChemNexa mock tests.

Register Free for Full Chemistry Practice

Thermodynamics and Thermochemistry Revision Guide for WBJEE 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 WBJEE 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 Thermodynamics and Thermochemistry

Concept Revision

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

Exam-style MCQs

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

Performance Practice

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

Top 20 Thermodynamics and Thermochemistry MCQs with Answers

These public questions are selected from the exact Thermodynamics and Thermochemistry 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.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

1. At constant T and P a spontaneous process has:

  • A. ΔG>0
  • B. ΔG=0 always
  • C. ΔH=0
  • D. ΔG<0
Answer: D
Explanation: Spontaneity requires ΔG<0.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

2. Which is a state function?

  • A. Path length
  • B. Enthalpy
  • C. Heat
  • D. Work
Answer: B
Explanation: Enthalpy is a state function.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

3. The correct relation is:

  • A. ΔG°=-RT lnK
  • B. ΔG°=RT lnK
  • C. ΔG°=-KRT
  • D. ΔG°=RT/K
Answer: A
Explanation: ΔG°=-RTlnK.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

4. Positive E°cell implies:

  • A. ΔG°<0
  • B. ΔG°>0
  • C. K<1 necessarily
  • D. No spontaneous reaction
Answer: A
Explanation: ΔG°=-nFE°.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

5. Which fundamental condition must be respected in solving Thermodynamics and Thermochemistry problems?

  • A. Ignore limiting conditions
  • B. Conservation of atoms and charge
  • C. Ignore units
  • D. Assume coefficients are one
Answer: B
Explanation: Atom and charge conservation are fundamental.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

6. At dynamic equilibrium relevant to Thermodynamics and Thermochemistry:

  • A. Forward and reverse rates are equal
  • B. All molecular motion stops
  • C. Concentrations must be equal
  • D. Catalyst is consumed
Answer: A
Explanation: At equilibrium forward and reverse rates are equal.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

7. A catalyst in Thermodynamics and Thermochemistry generally:

  • A. Changes ΔH
  • B. Changes K at fixed T
  • C. Lowers activation energy without changing K at fixed T
  • D. Changes ΔG°
Answer: C
Explanation: Catalysts affect kinetics, not equilibrium thermodynamics.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

8. Oxidation means:

  • A. Gain of protons
  • B. Loss of electrons
  • C. Gain of electrons
  • D. No oxidation-number change
Answer: B
Explanation: Oxidation is electron loss.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

9. Reduction means:

  • A. Gain of electrons
  • B. Loss of electrons
  • C. Increase in oxidation number
  • D. Loss of protons
Answer: A
Explanation: Reduction is electron gain.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

10. A Lewis acid is:

  • A. Electron-pair donor
  • B. Always proton donor
  • C. Always anion
  • D. Electron-pair acceptor
Answer: D
Explanation: Lewis acids accept electron pairs.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

11. A Lewis base is:

  • A. Always cation
  • B. Always oxidant
  • C. Electron-pair donor
  • D. Electron-pair acceptor
Answer: C
Explanation: Lewis bases donate electron pairs.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

12. For a first-order process, half-life is:

  • A. k/0.693
  • B. 1/(k[A]0)
  • C. [A]0/(2k)
  • D. 0.693/k
Answer: D
Explanation: t1/2=0.693/k.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

13. Arrhenius equation is:

  • A. k=EaRT
  • B. k=A/RT
  • C. k=Ae^(-Ea/RT)
  • D. k=Ae^(Ea/RT)
Answer: C
Explanation: Arrhenius equation relates k, Ea and T.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

14. 0.20 mol solute in 0.50 L solution has molarity:

  • A. 0.70 M
  • B. 0.40 M
  • C. 0.10 M
  • D. 2.50 M
Answer: B
Explanation: M=0.20/0.50=0.40 M.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

15. For a weak acid, larger Ka means:

  • A. Stronger acid
  • B. Weaker acid
  • C. No ionisation
  • D. Stronger conjugate acid
Answer: A
Explanation: Larger Ka means greater ionisation.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

16. At 25°C:

  • A. pH+pOH=7
  • B. pH=pOH always
  • C. pH+pOH=1
  • D. pH+pOH=14
Answer: D
Explanation: pH+pOH=pKw=14.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

17. Oxidation in an electrochemical cell occurs at:

  • A. Salt bridge
  • B. Wire
  • C. Anode
  • D. Cathode
Answer: C
Explanation: Oxidation occurs at the anode.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

18. Reduction in an electrochemical cell occurs at:

  • A. Wire
  • B. Cathode
  • C. Anode
  • D. Salt bridge
Answer: B
Explanation: Reduction occurs at the cathode.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

19. An electrophile is:

  • A. Always radical
  • B. Electron-pair acceptor
  • C. Electron-pair donor
  • D. Always negative
Answer: B
Explanation: Electrophiles accept electron pairs.

WBJEE Chemistry · Thermodynamics and Thermochemistry · Very Very Hard

20. Inductive effect is transmitted through:

  • A. Sigma bonds
  • B. Pi bonds only
  • C. Hydrogen bonds
  • D. Ionic lattice
Answer: A
Explanation: Inductive effect propagates through sigma bonds.

Login to Start Full Test

Thermodynamics and Thermochemistry Practice Tests

Thermodynamics and Thermochemistry Frequently Asked Questions

What causes most Thermodynamics mistakes?

Sign conventions for heat and work, confusing state functions with path functions, and using inconsistent units are common sources of error.

What does negative ΔG indicate?

For a process under the stated conditions, negative Gibbs free-energy change indicates thermodynamic spontaneity.

How should I revise Thermodynamics?

Build a one-page sign-convention and formula sheet, then practise problems that require choosing the correct relation rather than only substituting numbers.

Continue with another chapter to build connected concepts and strengthen your overall Chemistry preparation.

Continue WBJEE Chemistry

View all WBJEE chapters and testsBrowse all Chemistry PracticeCreate a free account