Numerical Data

Chemists and other scientists often require numerical data to answer questions or complete calculations.

Periodical tables offer a unique orgainizing format for numerical chemical data.   Two among a number of WEB based periodical tables available are the WebElements Periodic Table and the unique Periodic Table of Comic Books.

Probably the most extensive source of numeric data can be found in the databases available through database vendors such as STN International or Dialog. STN, for example, is a vendor for over 125 databases. One of these databases, NUMERIGUIDE, is a guide to the numeric data that can be found in the other databases. 

Among other sources for thermodyanmic data are the National Institute of Standards and Technology (formerly the National Bureau of Standards) and the JANAF (Joint-Army-Navy-Air Force)Thermochemical Tables. The latter source provides thermochemical data over a wide range of temperatures and also provides data for unstable and transient chemical species. A limited amount of thermodynamic data can be conveniently found in the Chemical Rubber Company Handbook of Chemistry and Physics. All three of these sources only provide thermodynamic data for organic compounds with two or fewer carbons. Lange's Handbook of Chemistry, N. H. Lange, ed., Handbbook Publishers, Inc., Sandusky, Ohio provides a more extensive compilation of thermochemical data for organic compounds.  An extensive listing of websites containing thermochemical and physical property data is maintained by the University of Illinois at Chicago Thermodynamics Research Laboratory.

Two sources for equilibrium or stability constants are Stability Constants of Metal-Ion Complexes, Section I: Inorganic Ligands and Section II: Organic Ligands, London, The Chemical Society, Special Publication, Burlington House and the IUPAC Stability Contstant Database, L. D. Pettit and H. K. Powell, compilers. The latter source is available on CD-ROM in the Montana Tech Library.

A number of companies have established WEB databases of various chemical and physical properties.  Some examples are given below:

• ASI Instruments, Inc. maintains a rather extensive list of dielectric constants. Dielectric constants are useful in predicting relative solvation abilities. 

• Flexware has developed a list of the critical pressures and temperatures of a number of compounds. Supercritical compounds, i.e., compounds at temperatures and pressures greater than their critical values have enhanced solvation properties.