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How To Choose Your First Class

General Chemistry

Two different general chemistry sequences are offered: the two-quarter set of courses, Chem 31A/B, and the single-quarter course, Chem 31M. Students should take either FULL Chem 31A/B sequence OR Chem 31M. It is important to take a complete general chemistry sequence to ensure the student has proper background in both content and lab skills before entering the organic chemistry sequence (Chem 33). Both sequences fulfill the general chemistry requirement at Stanford and arrive at the same endpoint, preparing students to enroll in Chem 33, an introduction to organic chemistry.

All students who are interested in taking general chemistry at Stanford must take the Autumn 2021 General Chemistry Placement Test before Autumn quarter begins, regardless of chemistry background. Note that students who place into general chemistry must start in Autumn quarter, as both sequences (31A and 31M) are only offered in Autumn.  Students can enroll for the General Chemistry Placement Test on Canvas, under the Quizzes tab on this page: Self Enrollment on Canvas.

Organic Chemistry

All students with AP or IB credit who are considering placing directly into Chem 33 must take the Autumn 2021 Chemistry 33 Placement Test. Students not placing into Chem 33 will be placed into Chem 31M. Please note that even though Chem 33 is offered in the winter and spring, you must still take the placement test in Autumn, as Chem 31M is only offered in Autumn quater. Students can enroll for this placement test on Canvas, under the Quizzes tab on this page:  Self Enrollment in the Chemistry 33 Placement Test on Canvas

General Placement Test information:

Students taking chemistry for the first time at Stanford need only take one of the above placement tests. The placement tests will open on July 31st. Students are encouraged to take the test BEFORE September to help better inform their enrollment decisions. Only students who have completed the placement test will have access to enrollment in general chemistry this Autumn. Placement decisions will be announced, and the enrollment hold will be lifted, in early September. Students who have taken AP or IB chemistry generally place into Chem 31M.

Math Background

While neither general chemistry sequence requires calculus, a solid foundation in algebra is essential. This includes comfort with algebraic expressions and manipulations, exponents and logarithms, functions and graphs, and dimensional analysis. As solid math skills are critical to success in general chemistry, students are also STRONGLY encouraged to take the math diagnostic in July and consider enrollment in the math SOAR program if advised. This program generallly begins near the end of July and will cover many of the essential math skills needed in general chemistry: (SOAR Mathematics Program - Mathematics (

Chemistry 31A and 31B

For students with moderate or limited prior chemistry experience, the Chemistry Department offers a two-quarter general chemistry sequence, Chem 31A and 31B. This sequence covers all essential topics in general chemistry, with an emphasis on problem solving. Chem 31A/B is offered only in the Autumn-Winter sequence, and 31A is a hard-coded prerequisite for 31B. Students who successfully complete the sequence can then proceed to Chem 33 (Organic Chemistry) in the Spring. Please consult the syllabus website for the syllabus and course calendar.

Chemistry 31M

Those with a strong high school chemistry background generally take Chem 31M, which is offered Autumn quarter only. Chem 31M covers the more advanced portions of the same topics covered in Chem 31A/B and moves at a faster pace. View the Chem 31M tentative course calendar here.

Chemistry 33

Students who earned a 5 on the AP Chemistry Exam have the option to begin with Chem 33, if they earn a passing score on the Autumn Chemistry 33 Placement Test. Chem 33 is generally offered in the winter and spring quarters, however students must take the placement test before the start of Autumn quarter in case they place into Chem31M (only offered in Autumn). 

Chemistry 121

A few students with an exceptionally strong background in chemistry, e.g., IB, A-levels, French Baccalaureate, German Abitur, or college transfer credits, may begin with Chem 121. These students should contact Dr. Megan Brennan for placement before the start of Autumn quarter. 

AP Credit in Chemistry

Premedical students should be forewarned that not all medical schools accept AP credit; students may need to take either a general chemistry course, 31A/B or 31M, or a more advanced chemistry course in order to qualify for some medical schools. It is therefore recommended that pre-med students with a 5 on the AP Chemistry Exam and who do not anticipate taking more advanced chemistry courses enroll in Chem 31M rather than enrolling directly in Chem 33. Students under other circumstances should consult with the Director of Undergraduate Studies, Professor Chris Chidsey.









Placement into Chem 33 requires department placement diagnostic. Students should self-enroll here: Self Enrollment in the Chemistry 33 Placement Test on Canvas


CHEM 31A+31B or 31M



Placement into Chem 31M requires departement placement diagnostic. Students should self-enroll here to take the placement test BEFORE Autumn quarter: Self Enrollment on Canvas.

Depending upon placemen test results students will enroll in EITHER Chem 31A or Chem 31M. Students cannot place directly into Chem 31B as it is part of a two-quarter sequence. 


Chem 31A