This textbook is written to meet the requirements of undergraduate students of B. Sc. Second year of all Indian universities. Comprising three parts Inorganic, Organic and physical, it comprehensively details All the principles of chemistry. Illustrations and diagrams are provided to help students in understanding the chemical structures and reactions. , highlights important laws, concepts and principles for a more focused learning, interesting examples and illustrations provided throughout the text, exercises based on questions from different University papers part–i: Inorganic Chemistry 1. Chemistry of Elements of first transition series 2. Chemistry of Elements of second and third transition series 3. Oxidation and reduction 4. Coordination Compounds 5. Chemistry of lanthanide elements 6. Chemistry of actinides 7. Acids and bases 8. Non-aqueous Solvents part–ii: Organic Chemistry 1. Electromagnetic spectrum: Absorption spectra 2. Alcohols 3. Phenols 4. Ethers and Epoxides 5. Aldehydes and Ketones 6. Carboxylic Acids 7. Carboxylic acid derivatives 8. Organic Compounds of Nitrogen part–iii: Physical Chemistry 1. Thermodynamics-i 2. Thermodynamics-ii 3. Chemical Equilibrium 4. Phase rule 5. Liquid-liquid Mixtures 6. Distribution law 7. Electrochemistry-i 8. Electrochemistry-ii.