The American Chemical Society (ACS) was started in 1876 by 35 chemists. It began publishing the Journal of the American Chemical Society in 1879 and Chemical Abstracts in 1907. There are over 158,000 members of ACS, and it is the largest scientific society in the world.
The ACS style of presentation is used in their over 50 journals. If you are publishing in a chemistry class or a scientific journal, this is the style you will use.
A good reference is from the University of Wisconsin-Madison libraries. It can be found at: http://www.library.wisc.edu/chemistry/research-help/write-and-cite/acs-style-guide/
A good source for citations is from the Penn State University library. It can be found at: http://www.libraries.psu.edu/content/dam/psul/up/pams/documents/QuickGuideACS.pdf