Many students wishing to take courses during the academic year or the summer may have questions about prerequisites, particularly given the automatic enforcement of certain prerequisites during registration. 

  • An override is not required if a student has taken the prerequisite course at OSU or has successfully transferred a course to OSU that articulates directly to OSU as a CH course with the same number as the OSU prerequisite course as documented in the data base for the student.
  • An override is needed if a transferred course does not articulate directly as the appropriate OSU course or the course has not been completed at an Oregon community college.

Prerequisite courses are listed in the OSU online catalog & Schedule of Classes for each course offered. You may be able to determine how the course you have taken at your previous school articulates to the course number at OSU and thus determine if you have the prerequisite by going to the following pages:

The second link provides chemistry articulation tables for all Oregon schools and a number of out of state schools. It indicates if a given transfer courses articulates directly as an OSU numbered course or as a course with a number (lower division (LDT) or UDT (upper division credit). The table further indicates if an LDT or UDT course is an acceptable substitute for an OSU course or sequence and can be used as a prerequisite.


If you need an override and believe that you have the prerequisites, you should fill out the Registration and Override Help Form.

For all sequence courses, enrollment in subsequent terms requires a passing grade in the previous term. No distinction is made between courses offered on campus or through ECampus. 

Plan ahead if you need an override!  Overrides can take 3-5 business days to process.


General Placement Guidelines:

CH 121 - 5 credits
The CH 121 sequence (CH 121, 122, 123) is only for students who have:

  • Little or no high school chemistry, AND
  • Concurrent enrollment in or successful completion of MTH 095 or higher.

A more gradual and thorough approach in this sequence will prepare students to take an advanced chemistry course such as CH 331. Students who do not place in MTH 095 should complete MTH 065 with a C or better and then enroll in MTH 095 concurrently with CH 121.

CH 231 - 5 credits
CH 231, 232, 233 is a general chemistry sequence of 15 credits intended for science, pharmacy, chemical engineering, pre-medical/pre-dental students, and others interested in a complete general chemistry sequence. Only students who have the following should enroll in CH 231:

  • At least one year of high school chemistry, AND
  • Successful completion of MTH 111 or higher OR concurrent enrollment in MTH 111 OR placement in MTH 112 or higher.

For more information, consult your academic advisor.

Students qualified to take CH 231 should NOT be placed in CH 121.

CH 331 - 4 credits

CH 331 and 332 are lecture courses covering Organic Chemistry; CH 337 is a combined lecture/lab course expanding on material in the first two. The three-term sequence is intended to satisfy the needs of students required to take a full year of organic chemistry with lab (pre-medical and other pre-professional students in particular). A student must have completed a year of general chemistry to be ready for this sequence.

Links to the OSU Online Catalog: