Chemistry: The Central Science
Multiple choice problems for general chemistry from the publishers of the textbook by Brown, LeMay, Bursten, and Burdge. Click on the "Jump to" pull-down menu at the upper left to get started. In addition to practice problems in multiple choice format, the site has many links to other chemistry sites, molecular models (requires the CHIME browser plugin), and more.

General, Organic and Biochemistry: Connecting Chemistry to Your Life
Multiple choice practice problems to accompany the textbook by Blei and Odian. After selecting a chapter, just click "Start" to begin.

Introduction to General, Organic, and Biochemistry
Accompanies the textbook by Bettelheim, Brown, and March. Multiple choice practice problems arranged by chapter.

Introductory Chemistry Quizzes
Practice quizzes in multiple choice format, arranged by chapter topic. By Karen Timberlake, author of the popular introductory chemistry textbook, Chemistry: An Introduction to General, Organic, and Biological Chemistry.

General Chemistry Online
Fred Senese's award-winning web site for general chemistry. It has many resources and links to other useful chemistry sites. He currently has only a few online exams of his own here, but it is expected that more will be added in the future.

ARIS
ARIS (Assessment, Review, and Instruction System) is an electronic homework and course management system, but students can currently access practice quizzes and other supplements without a login.  Choose a subject and textbook and then go to "Self Study" to access the material by chapter. From McGraw Hill Higher Education.

Organic Chemistry
Multiple choice problems arranged by chapter, such as alkenes, alkynes, alcohols, etc. Accompanies the textbook by Brown and Foote.

Organic Chemistry
More organic practice problems and other materials, from the publishers of the textbook by John McMurry. Problems are arranged by chapter.  The new site for the seventh edition of the textbook is here.

Preparation for Topics in College Chemistry
Eric A. Nelson's extensive general chemistry tutorials in pdf format, free for downloading and printing. Topics include unit conversion, names and formulas, gram-mole conversions and stoichiometry problems, molarity, acids and bases, and gas laws.

Interactive Tutorials
Tutorials and practice quizzes for general chemistry. "Flash card" quizzes on organic reactions are also available. From the Department of Chemistry, Ohio State University.

Organic Reaction Quizzes and Summaries
Review reactions by functional group and test yourself with a follow-up quiz. Well-organized and detailed. By Linda M. Sweeting, Towson University.