Below are some useful sources for finding physical and chemical properties.

Sigma-Aldrich
Lists common physical properties (boiling point, molecular weight, etc.) for chemical compounds that are available through the company.

CHEMnetBASE
Provides online access to information from the Combined Chemical Dictionary, the CRC Handbook of Chemistry and Physics, Polymers: A Property Database, Properties of Organic Compounds, and some other chemistry dictionaries. The Combined Chemical Dictionary (CCD), the CRC Handbook of Chemistry and Physics, and Properties of Organic Compounds are the most frequantly used resources.

Merck Index
Encyclopedia of chemicals, drugs, and biologicals that contains more than 10,000 monographs. Each monograph in this authoritative reference source is a concise description of a single substance or a small group of closely related compounds.

Knovel Scientific and Engineering Databases
Provides information on a number of chemical and physical properties for chemicals, esp. industrial chemicals. The interative tables and interactive graphs features also allow easy ways to manipulate data.

NIST Chemistry Webbook
Provides a number of physical properties such as thermochemical, thermophysical, and ion energetics data compiled by NIST under the Standard Reference Data Program.

ChemSpider
Provides search access to chemical compounds from hundreds of data sources. It provides both experimental and predicted properties data.

SpringerMaterials
Encompasses all volumes of Landolt-Börnstein New Series (largest and most respected compilation of data in physics and chemistry), the complete Linus Pauling Files (properties of inorganic solid phases), a subset of the Dortmund Database of Software and Separation Technology (thermophysical properties of pure liquids and binary mixtures), and other specialized databases.

DIPPR Chemical Database
Consists of experimental data and correlations of temperature-dependent properties for over 1,600 pure chemicals. Collected data have been evaluated, correlated, and checked for thermodynamic consistency.

PubChem
Available online through the NIH and NLM.

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