Teacher manual for AP* and Advanced Chemistry labs. Has both the printed version and a flash drive with teacher tips, a PDF of teacher version and editable Word student version.
The First Law of Thermodynamics states that energy is neither lost nor gained in a chemical process. This is paraphrased as “energy is conserved.” Reactions that release energy are known as exothermic reactions. Reactions that absorb energy are endothermic reactions.
The amount of heat energy involved in a process is referred to as enthalpy. Although the amount of enthalpy cannot be measured directly, scientists can determine how much it changes. In this lab, you will use the First Law of Thermodynamics to determine the change of energy in various reactions and combine the results to determine the enthalpy change of a related reaction.
How do you find the change of enthalpy in chemical reactions?
Students demonstrate that the heat q is dependent on reaction conditions but the change in enthalpy ΔH is a constant quantity. They will also discover and employ the additive nature of ΔH.
The student is able to design and/or interpret the results of an experiment in which calorimetry is used to determine the change in enthalpy of a chemical process (heating/cooling, phase transition, or chemical reaction) at constant pressure.
This experiment may require software and an interface for data collection.