Chemacro for Microsoft Excel—a tool to help you learn

The most common "spreadsheet" program is Microsoft's Excel application, available for both the Windows and the Mac OS platforms. Many versions of it are in common use at Dartmouth, but all of them have very much the same functionality and operating rules. With Excel alone, you can perform many very elaborate calculations quickly, and you can generate graphical representations of numerical data quickly and in a variety of formats. It is well worth your while to learn the basics of Excel, if you haven't already, and to learn how Excel data, graphs, tables, etc., can be copied and linked to Microsoft Word documents. These skills will serve you well in everything from homework to lab reports to undergraduate research to professional activites.

Excel has the ability to accept new commands and functions beyond those built into it. There are several ways to do so, and one of them, called an Add-In file, has been exploited to ease the numerical calculations associated with physical chemistry calculations. The Add-In described here and available through a link below on this page is called Chemacro. In Excel parlance, a macro is a new command or function, and this Add-In contains several macros designed for work in chemistry (or physics or engineering or ...). With this Add-In, you can:

"teach" an Excel spreadsheet (called a worksheet in Excel) the values of many common Universal Physical Constants (such as the speed of light, Avogadro's constant, etc.) so that Excel knows them by name, allowing you to type, for example, the word clite to stand for the speed of light,

calculate the molar mass of any element or compound using a special mathematical function that takes the chemical formula as its argument (along with two other arguments that signal the units Chemacro should use for the result: kg or g for mass, and mol or molecule—sybolized molec in Chemacro— for amount),

look up the physical meaning of and SI representation for any of hundreds of physical units,

convert any physical quantity from one unit to another through another special mathematical function,

produce quick and simple line graphs of selected data on a worksheet,

and generate a simple least-squares fit to worksheet values that you believe are related linearly.

Using and learning Chemacro is very easy. A complete manual is available as a pdf file, or as a web page, and the Add-In file itself is available as a compressed archive.

Note: the most recent version (as of late 2009) of Excel on either the Mac or Windows platform is, alas, not compatible with the plug-in architecture used by Chemacro. If you have an earlier version available, such as the Macintosh Office 2004 version, Chemacro will work quite well.