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.

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 (i.e. you can NOT enroll in 31B without first taking 31A). 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.

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, and provide the general chemistry necessary for other advanced courses.

General Chemistry Placement

Students who have and AP score of 4 or 5 or IB credit and do not wish to go directly into organic chemistry should enroll in the Chem31M sequence.  All other students who are interested in taking general chemistry at Stanford must take the Autumn 2022 General Chemistry Placement Test before Autumn quarter begins. 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 Autumn 2022 General Chemistry Placement Test here: Self Enrollment on Canvas. Once enrolled, take the placement test is under the Quizzes tab in this course.

Organic Chemistry

All students with AP, IB, or international credit who are considering placing directly into Chem 33 must take the Autumn 2022 General Chemistry Proficiency Test for placement into Chem 33 and other courses in the Chemistry and related departments. 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 quarter. Students can enroll for this placement test on Canvas, under the Quizzes tab on this page:  Autumn 2022 General Chemistry Proficiency Test for placement into Chem 33 and other courses in Chemistry and related departments.

Chemistry 33

Students who earned a 5 on the AP Chemistry Exam have the option to begin with Chem 33, the first quarter of organic chemistry, 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, the second quarter of organic chemistry. These students should contact Dr. Megan Brennan brennanm [at] for placement before the start of Autumn quarter. 

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 be available starting August 8th. Students should take the test BEFORE September to help better inform their enrollment decisions. Only students who have completed the placement test (or have AP/IB scores) will have access to enrollment in general chemistry this Autumn. Placement decisions will be emailed, and the enrollment hold will be lifted, in early September.

Students with Documented Disabilities

If you have a disability or required accommodations in high school, you should contact the Office of Accessible Education (OAE) as soon as possible. The OAE office is located at 563 Salvatierra Walk (phone 723-1066, TTY 725-1067) and their website is The OAE will evaluate the request, recommend appropriate accommodations. Note that the placement tests are NOT timed, therefore students can take as much time as needed.  If you need additional accommodations, please email your OAE letter to jks425 [at] You will get instructions for taking the Chemistry Placement Test from Dr. Jennifer Schwartz Poehlmann. 

Math Backround

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 generally begins near the end of July and will cover many of the essential math skills needed in general chemistry: (SOAR Mathematics Program - Mathematics (

Premedical Preparation in Chemistry

Premedical students should be forewarned that not all medical schools accept AP credit; students may need to take chemistry course sequence, 31A/B or 31M, or a more advanced chemistry course 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 should consult with Pre-Med advising for the most up to date recommendations.









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

Alternatively students can enroll directly into Chem 31M.


CHEM 31A+31B or 31M, IF placed into Chem 33



Students can enroll directly into Chem 31M. Students cannot place directly into Chem 31B as it is part of a two-quarter sequence.

If a student wishes to consider placement into Chem 33, this requires a department placement diagnostic. Students should self-enroll here: Self Enrollment on Canvas.


Chem 31A+31B or 31M, IF placed into Chem 33