Gateway Page

Table of Contents

Welcome to the Thermodynamics Tutorial! Thermodynamics is involved in a wide range of topics in chemistry. Generally it tries to describe how energy and matter interact and to predict whether particular changes will occur.


Energy, work, and a definition of thermodynamic systems and surroundings.

Heat and Enthalpy

A common form of energy, heat, is defined and related to energy. The difference between energy and enthalpy is explained here.

Thermochemical Equations

How to relate energy and enthalpy changes to chemical equations is described here.


Entropy describes the amount of disorder in a system. Here is a description of entropy and how knowing about entropy allows you to predict whether reactions will occur.

Free Energy

Whether or not a reaction will occur depends both on how disordered the energy and the mass becomes in the system. Free energy combines both these measurements, and also measures the amount of "useful" energy a reaction will produce or consume.

Thermodynamics Problem-Solving Procedure

Throughout the Thermodynamics Tutorial a procedure for solving thermodynamics problems has been developed. This is an overview of this procedure along with some examples showing how to use it.

To navigate between pages in a module, use the menu in the left-hand navigation bar. Home takes you back to this page. Table of Contents takes you to a list of all the tutoriasl so you can return to any spot in any module you were at previously. The Thermodynamics Gateway Page link will return you to this page. The module links take you to the first page in the corresponding module.

There are some common icons you will see used over and over in this tutorial. These icons and what they mean are listed below.

Back button. Click here to go back to the previous page. Next button. Click here to go to the next page.
Page tracking icon. These icons tell you which page in the module you are on and how many pages there are in all in the module. Debriefing icon. Click here at the end of a module to go to a debriefing that will test what you have learned in the module.
The mouse icon alerts you to an interactive element on the page that may require you to click somewhere, enter some information, or somehow interact with the page.
Throughout each module you will find certain technical words you may be unfamiliar with. These words will be emphasized like this, and will be followed by the book icon shown at left. Clicking on the book icon pops up an alternate definition of the term in plain English. Try clicking on the one at left to see how it works. Don"t forget to close the alternate definition windows when you are done with them!
Occasionally in the modules you will need to apply something you have learned earlier in the course, perhaps in another tutorial. Clicking on the test tube icon (like the one at left) pops up an accessory window that reviews what you may have forgotten or need to review. Click on the test tube at left to see how this works. Don"t forget to close accessory windows when you are done with them!
This reference was used repeatedly in the development of this module.

John W. Moore, Conrad L. Stanitski, James L. Wood, John C. Kotz, and Melvin D. Joesten. The Chemical World: Concepts and Applications (2nd edition). Saunders College Publishing, New York (1998).

Selected thermodynamic values used in some of the modules were taken from:

Ignacio Tinoco, Jr., Kenneth Sauer, and James C. Wang. Physical Chemistry: Principles and Applications in Biological Sciences (2nd edition). Prentice-Hall, Inc., Englewood Cliffs, N.J. (1985).