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Citing Sources: ACS Style

Who uses ACS style?

ACS (American Chemical Society) style is the standard citation style for chemistry.

ACS Style

Common ACS Examples for UP Students

For detailed style guidelines see: Chapter Data & Datasets

For an online book or encyclopedia:

Cyclohexane. In CRC Handbook of Chemistry and Physics, 101st ed.; Rumble, J. R., Ed.; CRC Press, 2020. (accessed 2020-08-19). (CAS RN: 110-82-7).

For an online database:

Cyclohexane. The Merck Index Online. Royal Society of Chemistry, 2013. (accessed 2020-08-15). (CAS RN: 110-82-7).

Cyclohexane. SDBSWeb. National Institute of Advanced Industrial Science and Technology, n.d. (accessed 2020-08-17). (CAS RN: 110-82-7).

Cyclohexane. SciFinder. CAS, n.d. (accessed 2020-03-28). IR spectral data obtained from Bio-Rad Laboratories. (CAS RN: 110-82-7).

For detailed style guidelines see: Chapter Safety Data Sheets

Found through third-party provider:

Cyclohexane; CAS RN: 110-82-7; 650455; ver. 6; Sigma-Aldrich: St. Louis, MO, January 31, 2017. Retrieved from University of Portland MSDS Online. (accessed 2020-08-15).

Found on manufacturer site:

Cyclohexane; CAS RN: 110-82-7; 227048; ver. 6.4; Sigma-Aldrich: St. Louis, MO, January 23, 2020. (accessed 2020-08-15).

Citing an experiment or appendix from the course lab manual? Use the ACS format for citing a chapter in a book.


Bard, R.; Bard, R.; Breuer, K.; Jacob, W.; Osborne, D.; Schacherer, L.; Taylor, B.; Thompson, W.; Valente, E.; Wood, W. Experiment A2: Distillation of a Mixture of Cyclohexane and Toluene. In CHM 375 Organic Chemistry I Laboratory Manual; University of Portland, 2021-2022; pp 25-32.

The Chemical Abstracts Service (CAS) Registry has 187 million organic and inorganic substances. Each substance has been given a unique registry number (RN) and that is the most accurate way to search for information about it. Searching by substance name can be less accurate since there are different naming systems.

The registry number might be referred to as:

CAS Registry Number
CAS Number

The number has dashes which are considered part of the number. For example, the CAS RN for Cyclohexane is: 110-82-7. Include the dashes when searching by CAS RN in various databases, and also when including the number in a citation for a source. 

Other Writing Guides

Citation Management Tools

RefWorks can be used to gather sources in one place and automatically generate bibliographies in APA, MLA, Chicago, and many other styles.

Mendeley is another citation management tool and an alternative to RefWorks. It is free up to 2GB of storage. Students are not likely to need more storage than that for their projects. 

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