Thermochemistry and Energy Use


Module Overview

This module focuses on thermochemistry, which is covered in either general chemistry I or general chemistry II depending on institutional preferences. The module consists of several activities. Activity 1 consists of an initial orientation to energy systems: completed by students outside of class and followed by an an in-class activity where students calculate the energy required to prepare food both one time and over the course of a year; products created by the generation of energy for kitchen use; and the energy saved by reducing solvent usage in the synthesis of compounds used in PCR testing for COVID-19.

Activity 2 is designed to be completed outside of class and focuses on connections between energy usage and economic/social considerations. Activity 3 includes an introduction to renewable energy and problems to be done in class or as homework where students: calculate the energy of a phase change; calculate the change in energy for various physical and chemical processes, using Hess’s law and other thermochemical concepts; examine components of hydrogen storage systems; and evaluate different methods of hydrogen storage. 

 

Module Goal

At the conclusion of this module, students will be able to use thermochemistry concepts and calculations to evaluate energy changes for processes that also have clear environmental and societal consequences.

Audience

First-year general chemistry undergraduates

Class Time Requirement

Between one and two weeks of instruction

Module Authors

Matt Fisher, Saint Vincent College; Jennifer Tripp, University of San Francisco

Module Summary

Assumed Prior Knowledge

Students should be able to demonstrate the following skills and concepts to successfully begin this module:

  • Knowledge: Stoichiometry, Lewis structures, intermolecular forces and phase changes (knowledge of gas laws is optional depending on whether instructor chooses to incorporate some optional activity questions)
  • Skills: Stoichiometric calculations
  • Abilities: Algebraic mathematical calculations, drawing conclusions from data, plotting, visualization

 


Learning Objectives

Students will be able to:

  1. Explain energy changes involved in phase changes and chemical reactions through appropriate application of thermochemical concepts.
  2. Effectively use appropriate thermochemical calculations to determine energy changes for a process.
  3. Identify components of the system(s) that provides energy to meet local (home or college/university) needs as well as inputs and outputs.
  4. Explain the relationship between access to energy/energy use and sustainable development as reflected by economic activity.
  5. Apply multiple criteria in decision making.

Special Resources

The first part of activity 1 and all of activity 2 will require computers with Internet access. However, these are designed to be done outside of class if the instructor chooses.

Unit Overview

 

Unit 1: Home and Laboratory Energy Use

 

1.1

Pre-class activity on energy systems (30 minutes outside class) Questions 1 through 6. Short lectures can be given in class or via prerecorded videos prior to starting Question 7 in Activity 1. Total time for lectures is around 50 minutes. Lecture topics prior to working on questions 7 through 15 in Activity 1 would include heat capacity calculations, energy changes for chemical reactions, and phase change calculations. More detailed information can be found in the thermochemistry module lecture notes (a separate file). 

1.2

Collaborative activity (45-60 minutes in class) Working in pairs or small groups on calculations for home energy use (Activity 1 Part B questions 7 through 17). Activity 1 Part B questions 18 and 19 could be completed either in class or outside of class depending on time.

1.3

Activity 1 Part C questions 20 and 21 can be completed either in-class or outside of class; in-class completion will likely require 20-30 minutes.

1.4

Activity 1 Part C questions 26 and 27 require access to internet resources (PubChem, 12 Principles of Green Chemistry) and so will likely need to be completed outside of class.

Unit 2: Energy, Economic Development, and the Transition to Renewable Energy

 

2.1

Outside of class activity focused on information available from the Our World in Data website. Estimated time for completion roughly 30 minutes. 

Unit 3: Hydrogen Storage of Electricity from Renewable Sources

 

3.1

Short lecture on renewable energy (10-15 min, PowerPoint slides are provided), calculations (either instructor-led or in groups in class - Part A questions 1-7)) on electricity generated by a wind turbine, amount of hydrogen generated, and storage of gas and liquid. Phase change calculations are a review of activity 1 (30-45 min). 

3.2

Lecture on thermodynamic standard state, Hess’s law (use ammonia as example), and enthalpies of formation (30 min). More detailed information can be found in the thermochemistry module lecture notes (a separate file). Part B questions 1-10 can be started in class, and the rest assigned as homework (should take about an hour).

3.3

Capstone assignment - Students need to assess different methods of hydrogen storage and write a letter advocating for which one they would choose to use at a wind energy facility. (homework, possibly as a group. Completion time varies depending on how much research is done.)

Download Module

Thermochemistry Includes:

  • Module Overview Document
  • Units 1-3
  • Formative Assessments
  • Summative Assessments

UN SDGs

This module references the following U.N. Sustainable Development Goals (SDGs):

 



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About the Green Chemistry Module Project

The ACS Green Chemistry Instiute has partnered with chemistry instructors from over 45 institutions to develop green chemistry education resources for undergraduate students studying general and organic chemistry.