Exothermic and Endothermic Reactions: Experiments and Definitions

The video is a lecture presentation on exothermic and endothermic reactions. The presenter explains the definitions of these reactions and demonstrates two experiments to determine whether a reaction is exothermic or endothermic. The first experiment involves mixing hydrochloric acid and sodium hydroxide, while the second experiment involves dissolving potassium chloride in water. The presenter uses thermometers to measure temperature changes and explains the concept of the surroundings in each reaction. The video concludes with a summary of the steps to determine whether a reaction is exothermic or endothermic.