This textbook provides a comprehensive guide to the fundamentals of inorganic and organic chemistry for participants in chemistry and environmental protection competitions, national and international chemistry Olympiads, chemistry candidates and students of chemistry, medicine, dentistry and pharmacy.Sample problems and solutions are provided for a significant number of the topics and will be a useful and interesting tool for developing skills of analysis, comparison, generalisation, and searching for relationships and dependencies.Serious attention is paid to the redox processes taking place in all cases of inorganic and organic objects. The book will enable students to determine the degrees of oxidation of the individual constituent atoms of molecules, correctly identify the oxidant and reductant, and the changes in the degrees of oxidation at electronic transitions.The book also includes qualitative reactions for identifying the most important ions and elements, as well as characteristic reactions for determining the functional groups and the membership of a molecule in a particular class of organic compounds