CK-12 Foundation
Ck 12: Flex Book Textbooks: Chemistry Second Edition
[Free Registration/Login may be required to access all resource tools.] A complete, web-based, multi-media textbook covering a wide variety of Chemistry concepts.
Other
American Academy of Allergy, Asthma and Immunology
This resource describes an organization that is involved in studies and treatments of allergies. Research and education are also important parts of this organization.
Oklahoma State University
Oklahoma State University: Acid Base Overview
Beginning with the example of the hydrangea, this page gives a good overview of acid-base chemistry.