JEE ADVANCED · JEE MAIN · PHYSICAL CHEMISTRY
THERMO-
DYNAMICSComplete JEE Study Module with PYQs
50+ 5 30+ 10+
Solved
Pages Chapters PYQs
Examples
Laws of Thermodynamics · Enthalpy · Entropy · Gibbs Energy · PYQs · Solved Examples
Concepts · Key Formulae · Important Tables · Memory Tricks · JEE Tips
For JEE 2025-26 | Covers Complete NTA Syllabus
📋 TABLE OF CONTENTS
01 Introduction to Thermodynamics 4
Systems · Properties · State Functions
02 Laws of Thermodynamics 9
Zeroth · First · Second · Third Law
03 Thermodynamic Processes 15
Isothermal · Adiabatic · Isobaric · Isochoric · P-V Work
04 Enthalpy & Thermochemistry 22
Hess's Law · Formation · Combustion · Bond Enthalpy · Born-Haber
05 Entropy, Spontaneity & Gibbs Energy 33
Entropy Factors · ΔG = ΔH − TΔS · Equilibrium Constant
JEE PYQ Practice Sets 40
Chapter-wise Previous Year Questions with Answers
Solved Step-by-Step Examples 45
10 Fully Solved JEE Problems with Detailed Solutions
Quick Reference Formulae Sheet 50
All Key Equations at a Glance
Complete JEE Study Module | 50+ Pages | 30+ PYQs | 10+ Solved Examples Page
,THERMODYNAMICS · Physical Chemistry · JEE Advanced | JEE Main
Memory Tricks & JEE Tips 52
Mnemonics · Important Values · Exam Strategy
📌 How to Use This eBook
Read each chapter concept section first, then attempt PYQs without looking at answers.
After attempting, check the step-by-step solution. Mark questions for revision.
Use the Quick Reference sheet during revision week before the exam.
🌡 CHAPTER 1
Introduction to Thermodynamics
────────────────────────────────────────────────────────────
Thermodynamics is the branch of science that deals with the relationships between heat, work,
temperature, and energy. In chemistry, it helps us understand why reactions occur, how much
energy is involved, and whether a process is feasible under given conditions.
💡 Definition: Thermodynamics is the study of energy transformations and the laws
governing these transformations, particularly the interconversion of heat and other
forms of energy.
1.1 The System, Surroundings & Boundary
In thermodynamics, we define the part of the universe under observation as the SYSTEM.
Everything outside the system is the SURROUNDINGS, and together they make the
UNIVERSE.
Term Definition Example
System The specific macroscopic portion under study Reactants in a beaker
Surroundings The rest of the universe interacting with the Beaker, air, room
system
Boundary Real or imaginary wall separating system & Walls of the beaker
surroundings
Universe System + Surroundings Everything
Types of Boundaries
◆ Rigid / Flexible —A rigid boundary does not allow volume change; a flexible boundary (like
a piston) does.
◆ Permeable / Impermeable —A permeable boundary allows matter to pass; an
impermeable boundary blocks matter.
◆ Adiabatic / Diathermic —An adiabatic boundary does not allow heat transfer; a diathermic
boundary allows heat exchange.
1.2 Types of Systems
Complete JEE Study Module | 50+ Pages | 30+ PYQs | 10+ Solved Examples Page
, THERMODYNAMICS · Physical Chemistry · JEE Advanced | JEE Main
System Type Matter Energy Example
Exchange Exchange
Open System ✓ Yes ✓ Yes Open beaker, living organism
Closed System ✗ No ✓ Yes Sealed flask (diathermic walls)
Isolated System ✗ No ✗ No Thermos flask, ideal calorimeter
✅ JEE Trick: Remember "OCI" — Open (both), Closed (energy only), Isolated
(neither).
The human body is an open system. Earth as a whole approximates a closed system.
1.3 Thermodynamic Properties
Extensive vs. Intensive Properties
Extensive Properties Intensive Properties
Depend on amount of matter Independent of amount of matter
Additive in nature Non-additive
Double on doubling the system Remain same on doubling
Examples: Mass, Volume, n, U, H, G, S Examples: T, P, density, molarity, pH
💡 Key Rule: An extensive property per unit amount becomes intensive. E.g., Mass
(extensive) ÷ Volume (extensive) = Density (intensive).
Ratio of two extensive properties = always intensive property.
1.4 State Functions vs. Path Functions
State Functions Path Functions
Depend only on initial and final states Depend on the path taken
Independent of path Different values for different paths
Represented with Δ (delta) Cannot use Δ notation
Examples: P, V, T, n, U, H, G, S Examples: Work (w), Heat (q), Heat Capacity
1.5 Internal Energy (U)
Internal energy (U) is the total energy stored within a system — it includes kinetic energy
(translational, rotational, vibrational) and potential energy of all constituent particles.
Internal Energy U = (f/2) nRT
For ideal gas only; f = degrees of freedom
◆ ΔU depends only on initial and final states (state function)
Complete JEE Study Module | 50+ Pages | 30+ PYQs | 10+ Solved Examples Page