This Handbook is primarily aimed at students of Natural and Technological Sciences, in which Thermodynamics is a structural cognitive subject of theoretical and applied knowledge. This Handbook consists of two Parts. The first one contains answers to thought questions and the second one contains solutions to problems. The selection of this specific material was made with criteria clearly focused on the learning objective of consolidating the corresponding cognitive subject. Special emphasis is given to documenting the answers to theoretical questions, as well as to the detailed presentation of the thinking process that leads to solving each problem. Through the comprehensive study of this handbook, the reader learns to become familiar with the treatment of thermodynamic problems, while also gaining a deep understanding of the acquired knowledge.