These resources collect information on the most commonly encountered compounds and their most basic properties. If you are not finding an entry under the first chemical name that you try, try another synonym for that same compound or in the case of some of the sources, draw the structure of the compound you are looking for. Then try one of the more comprehensive sources (other tabs) or contact Jeremy (contact info on the left) if you are still having trouble finding the data you need.
Both Wikipedia and Wolfram Alpha can be quick and easy to seach when it come to chemical and physical properties. But before you use these resources, please consider the following when searching each source.