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Frequently Asked Questions

Course Content

What are the differences in content between the two general chemistry sequences?

Both sequences arrive at the same endpoint. Chem 31A/B will cover the material over two quarters with an emphasis on problem solving, while Chem 31M will cover the more advanced portions of the same material in one quarter. Both courses also include a lab component, which will provide practice with essential skills, techniques, and instrumentation needed in advanced chemistry labs.


How many units are each of the courses?

CHEM 31M is five units. CHEM 31A and Chem 31B are five units each.

Will Chem 31M be offered in the Winter?

No. Chem 31M will be offered only in the Autumn.

Will the Chem 31A/B track be offered in Winter and Spring?

No. Chem 31A/B will only be taught in the Autumn-Winter sequence (and Summer). Therefore, if you are planning to take this course, you must take Chem 31A in the Autumn or wait until the next year.

Can a student switch from Chem 31M to Chem 31A before the Registrar's deadline in Autumn quarter?


Can a student start directly in Chem 31B if they have placed into 31M?

No. Students cannot skip 31A and enroll directly in 31B, as this is a linked sequence. Each general chemistry sequence is designed to provide appropriate background in both lecture and lab content, so students are prepared for a successful start in organic chemistry (Chem 33). 

Placement and Advising

How do I choose between the two general chemistry sequences?

All students who are interested in taking general chemistry at Stanford must take the Autumn General Chemistry Placement Test BEFORE Autumn quarter begins, regardless o chemistry background. The Chem 31A/B sequence is prioritiezed for students with minimal background in chemistry and generally, students with AP/IB background tend to place into Chem 31M. 

You will receive feedback about your recommended placement based on your performance on that test during the first week of September. If you are told that either sequence is recommended for you, then you should compare the content and pace of the two sequences before making your decision (the syllabi for both courses are posted at Generally students with AP/IB background feel quite comfortable in Chem 31M.

Where do people with a 5 on the AP chem exam belong?

Students who earned a 5 on the AP Chemistry exam have the option to take the Chem 33 Placement test instead of the General Chemistry Placement test (How To Choose Your First Class - Department of Chemistry (  Please remember to take the placement test before the start of Autumn quarter, as students who do not place into Chem 33 will need to enroll in Chem 31M, which is only offered in Autumn. 

Students who take Chem 31M or Chem 31A/B will forfeit 5 or 10 units respectively of their APcredit in chemistry. However, premedical students should be forewarned that a few medical schools do not accept AP credit, and thus a student may need to take either a general chemistry course or a more advanced chemistry course to qualify for those few 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 consdider enrolling in Chem 31M rather than enrolling directly in Chem 33. Further questions regarding pre-med curriculum should be directed to the pre-med advising team: Planning for Medical School - Stanford Undergrad.

Which sequence should a potential chemistry or chemical engineering student take?

A potential chemistry or chemical engineering student should take the sequence appropriate to his or her background, based on their placement test results. Both sequences fulfill the general chemistry requirement, and both will give a student a proper background to go on in further study.

If a student takes Chem 31M and does poorly, should they take Chem 31B the following quarter?

No.  Chem 31A is a prerequisite for Chem 31B, and the material covered in Chem 31B will only cover half of the material in Chem 31M. If you need to retake Chem 31M, you must re-enroll in Chem 31M in the following Autumn quarter.

Can a student take Chem 31M and Chem 31B or Chem 31A and Chem 31M?

No. The tracks cover the material at different paces, so it is not appropriate to mix the two. Again, 31A is a prerequisite for 31B, so it is not possible to go from Chem 31M to Chem 31B.

Which course sequence, Chem 31A&B or Chem 31M, will be most helpful in my application to medical schools?

Students should take the sequence appropriate to his or her background, based on their placement test results.

For details on premedical preparation, consult the Steps for Planning for Graduate and Professional School. Stanford University will tell all medical schools that Stanford views both sequences as equivalent. Both Chem 31A&B and Chem 31M are rigorous preparatory courses and will be perceived as such by medical school admissions officers. If your placement test suggests that either sequence could be appropriate for you, then you should choose based on your current goals, ambition, and confidence for the study of chemistry as part of your undergraduate education rather than basing your choice on your plans for professional school.