What is Internal Energy, Enthalpy and Energy Diagrams? | Thermodynamics 03 | Javed Chem Wallah

Welcome to Lecture 03 of our Thermodynamics series! In this 28-minute masterclass, we explore the core concepts of heat transfer, energy changes, and reaction profile diagrams in physical chemistry. TIMESTAMPS: 00:00 - Introduction to Thermodynamics Lecture 03 00:45 - What is Internal Energy (E)? 02:15 - Internal Energy in Exothermic vs. Endothermic Reactions 03:30 - Units of Energy (Joule, Erg, Calorie) & Conversions 05:00 - Introduction to Enthalpy (H) & Heat Content 08:20 - Enthalpy Changes (Delta H) at Constant Pressure 11:30 - Enthalpy in Exothermic vs. Endothermic Reactions 13:15 - Standard Units of Enthalpy (kJ/mol, kcal/mol) 15:00 - Introduction to Energy Profile Diagrams 18:10 - Exothermic Reaction Energy Profiles Explained 21:30 - Endothermic Reaction Energy Profiles Explained 24:15 - Concept of Activation Energy (Ea) 26:45 - Summary, Key Takeaways & Exam Tips IN THIS LECTURE: • Internal Energy (E): We break down the total internal energy of a system and analyze how internal energy changes determine whether a reaction releases energy (exothermic) or absorbs energy (endothermic). • Units of Measurement: A complete breakdown of energy and force units including Joules (J), Ergs, Dynes, and Calories (cal), along with their key conversion factors. • Enthalpy (H): We define enthalpy and state functions, showing how enthalpy changes (Delta H) relate to heat content and system pressure during exothermic and endothermic processes. • Energy Profile Diagrams & Activation Energy (Ea): Learn how to read and draw potential energy curves for both endothermic and exothermic reactions, identifying reactants, products, transition states, and activation energy. Whether you are preparing for board exams or competitive tests, this video gives you a clear, structured understanding of key thermodynamic principles. Don't forget to like, comment with your questions, and subscribe to Javed Chem Wallah for more chemistry lectures!