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Finding Information for General Chemistry Laboratory Work: Popular Sources of Physical and Chemical Properties

This guide will help students locate and evaluate information needed to succeed in the general chemistry laboratory at the University of Pennsylvania.

The following tools may be useful in locating physical and chemical properties of the substances that you are using in your general chemistry laboratory experiments.  Please be sure to reference the source from which you retrieved the value that you cite in your laboratory report or notebook.

CRC Handbook of Chemistry and Physics

The CRC Handbook of Chemistry and Physics is a classic resource containing critically evaluated data in all areas of chemistry and physics.  Penn has access to this work in print at several libraries, as well as online.  To locate the most recent print editions, please visit

Combined Chemical Dictionary

The Combined Chemical Dictionary (CCD), as its name implies, combines several smaller dictionaries of substances and their properties, including the Dictionary of Organic Compounds, the Dictionary of Inorganic and Organometallic Compounds, the Dictionary of Natural Products, the Dictionary of Commonly Cited Compounds, and the Dictionary of Drugs, among others.  It is searchable by name, formula, CAS Registry Number, and structure, as well as being useful for profiling substances by their properties.  Entries are edited by experts in the field, with references to the primary literature from which the values come.  It also includes safety and hazards information for many substances.

NIST Chemistry Web Book

The NIST Chemistry Webbook ( is produced by the National Institute of Standards and Technology, under the Standard Reference Data Act.  The NIST Webbook contains data on around 40,000 organic and small inorganic substances, including thermochemical data, reaction thermochemistry data, IR, MS, UV/Vis, GC, electronic and vibrational spectra, ion energetics data, constants of diatomics, and thermophysical properties of fluids.  Note that not every substance has every type of data available.

NIST does a very good job of indicating the source of all data points, and, when a value presented represents the average value observed for that property, it links to the individual data points from which the value was computed.

The NIST Chemistry Webbook is free to use and represents your tax dollars at work!

Merck Index

The Merck Index has been produced for over 120 years, most recently by the Royal Society of Chemistry.  It contains information about over 11,500 substances that fall into the categories of drugs, agricultural agents, natural products, organic substances, and other substances of biological or agricultural interest, and its records are edited by experts in the field.

Citing Information Sources

The following recommendations are taken or derived from information provided in Chapter 14 of the ACS Style Guide.

Journal Articles:

LastName, Initials; LastName, Initials.  Journal TitleYear, Volume, Pages.

Example: Scientist, V. I.; Student, U. G. Journal of Very Important Science. 2018, 26, 123-125.



LastName, Initials; LastName, Initials. Chapter Title. In Book Title, Edition Number (if any); Publisher: Place of Publication, Year; Volume Number (if any), Pagination.

Note: if the book is an edited book, the abbreviation Ed. or Eds. should come after the editor’s name.

Example: Scientist, V. I., Ed.  Properties of Obscure Compounds.  In The Best Physical Properties Ever Recorded, 6th Ed.; University of Pennsylvania Libraries Press: Philadelphia, PA, 2017, 127.


Free Databases:

Database Name.  URL (accessed Month DD, YEAR).  DATABASE Registry Number NUMBER.

Example: NIST Chemistry Webbook. (accessed October 1, 2018).  NIST Chemistry Webbook Permanent Link

Fee-based Databases:

Database Name, Version; Publisher: Place of publication, year.  DATABASE Registry Number NUMBER (accessed Month, DD, YEAR).

Example:  CRC Handbook of Chemistry and Physics; CRC Press Taylor & Francis Group.  CRC Number HBCP 102543 (accessed October 1, 2018).

When Do I Need to Read Further?

All of the resources on this page have assembled property values that were originally published elsewhere and have presented them in one easy-to-use location.  They also reference the primary literature in which the values were found.  This naturally raises the question of what one should cite: the handbook/dictionary in which you found the value or the original journal article from which they obtained it.  Here are some things to take into consideration.

  • You are only allowed to cite something that you have actually read.  Therefore, if you haven't read the original article, you aren't allowed to cite the original article.  Period.  End of story.
  • You should read and cite the original article any time you have a question about the conditions under which the property values were observed.
  • You should read and cite the original article any time the value that you are seeing in a secondary source does not agree with that found in other secondary sources.
  • You should read and cite the handbook/dictionary/database any time you choose not to read the original article.
  • You should ask your professor/TA if you are unsure when to read the original article.