International Critical Tables of Numeric Data, Physics, Chemistry and Technology, 7 volumes and index (first electronic edition).
Originally published for the National Research Council, ICT offers data on physical, thermodynamic, mechanical, and other key properties. Many tables are interactive. The full text of the original print version is available in PDF format. Information has been indexed to allow fielded searches (example: find all alcohols with a boiling point between 50-100 Celsius). Results can be manipulated in spreadsheet-like tables allowing you to sort and select only the information you need.
Knovel Critical Tables
Contains tables of physical, solvent, and thermodynamic properties. Each table is fully interactive and searchable by keyword and numeric property value.
Smithsonian Physical Tables (ninth revised edition)
Comprising 901 tables concentration on a broad scope of common physical and chemical data. All entries in the index are hyperlinked to their page numbers.
Gateway to science and technology information provided by U.S. government agencies, including research and development results.
Guide to data on chemical substances, including boiling and melting points, specific gravities, evaporation rates, vapor densities, water solubilities, and EPA codes. Also includes molecular or structural images of substances. Searchable by chemical name, molecular formula, molecular weight, CAS registry number, and chemical structure.
Molecule of the Month
Features a new molecule every month, usually a substance of current, recent, or renewed interest.
A gateway to the data collection of the National Institute of Standards and Technology.
Provides properties of the elements.
WWW Chemistry Guide
A collection of links for chemists and researchers involved in organic, biochemical, computational, medicinal and/or other chemistry research.
Web Study Site
Assists high school and college students with introductory chemistry coursework.