The Common Compound Library available on this site contains Ka values for most common monoprotic and polyprotic acids, along with other physical properties.
Advanced Chemical Development, Inc. also offers ILAB, an online service that includes a pKa database containing about 9000 compounds. You can also use their software to predict pKa's from molecular structures.
You can also find acid pKa data using Cambridge Software's ChemFinder.
Author: Fred Senese email@example.com
Copyright © 1997-2010 by Fred Senese
Comments & questions to firstname.lastname@example.org
Last Revised 08/17/15.URL: http://antoine.frostburg.edu/chem/senese/101/acidbase/faq/print-pka-on-the-web.shtml