LAB 1: Energy Changes During Chemical Reactions BACKGROUND One form of energy from a chemical reaction is heat. Reactions with heat energy can be classified as either exothermic or endothermic. Think of these reactions as opposites from one another. . Exothermic reactions transferring energy into the surroundings = heat released . Endothermic reactions taking in energy from their surroundings = heat absorbed. During both reactions, you can observe their effects based on the feeling of warmth. When heat energy is released in an exothermic reaction, the surroundings will get warm. This is how you would know an exothermic reaction might possibly be occurring. With endothermic reactions, the temperature drops, indicating that heat energy was absorbed. OBJECTIVE AND PRE-LAB QUESTIONS In this lab, you will conduct two different experiments and classify them as either exothermic or endothermic. Prior to the start of this lab, answer the following questions: 1 - What is the relationship between temperature and an endothermic or exothermic reaction? 2 - How would you know that an exothermic or endothermic reaction took place during an experiment? 3 - What are some examples of exothermic reactions? PROBLEM QUESTION Read the background and procedures for both experiments. Write a problem question for both of these experiments. HYPOTHESIS Make a hypothesis (educated guess) for both of the experiments. 1 ) 2)