There are three introductory chemistry pathways:
- CHEM 120 — Principles of Chemistry
- CHEM 142, 152, 162 — General Chemistry
- CHEM 145, 155, 165 — Honors General Chemistry
In addition, we also offer CHEM 110 – Introduction to General Chemistry, for students who did not have high school chemistry or had it a long time ago, and plan to take CHEM 142.
Students take one of these pathways. Credit is not allowed for both CHEM 120 and 142, for example, or for both CHEM 120 and 145, or for both CHEM 142 and 145.
CHEM 142, 152, and 162 are offered every quarter, including summer. CHEM 142, 152, 162 is also available evenings if you start the sequence in autumn quarter. The CHEM 145 sequence starts only in autumn quarter.
What Chemistry Course Should I Take?
In brief...
- CHEM 110. Students who plan to take CHEM 142 but didn't have high school chemistry, or took it a long time ago, take CHEM 110 before CHEM 142.
- CHEM 120 is taken by students planning on majoring in nursing or another major that recommends this chemistry course.
- Students planning on science or engineering majors and premed students take the CHEM 142 or 145 series.
- CHEM 145. Students with a strong background in high school chemistry and an interest in chemistry or biochemistry as a major, and who have completed the first college quarter of calculus or will be taking it concurrently, should take the CHEM 145 series.
Read through the chemistry department's information for more detailed information. It is important that you have an adequate math background for the chemistry course you plan to take, and the department's recommendations are described there.
Organic Chemistry Sequences
At the UW, you take organic chemistry (if required by your major) after you take introductory chemistry. There are four organic chemistry pathways:
- CHEM 220 – Introduction to Organic Chemistry
- CHEM 223, 224 – Organic Chemistry, Short Program
- CHEM 237, 238, 239 – Organic Chemistry
- CHEM 335, 336, 337 – Honors Organic Chemistry
Students take one of these pathways. Credit is not allowed for both CHEM 220 and 223, or both CHEM 223 and 237, etc.
Unlike introductory chemistry, the organic chemistry courses are not offered every quarter. CHEM 220 is usually offered winter quarter, and the next course in the series, CHEM 221, is usually offered only spring quarter.
CHEM 223, 224 is an autumn, winter sequence. It is also offered intensively in summer quarter, CHEM 223 in the first half of the summer and 224 in the second half.
CHEM 237, 238, and 239 are offered most (but not all) quarters, and the sequence is also available in the evening if you start it in autumn quarter.
The CHEM 335 sequences starts only in autumn quarter.
CHEM 220 is taken by students planning on majoring in nursing or another major that recommends the CHEM 120, 220 (and sometimes 221) sequence. Most science majors that require organic chemistry will accept either the CHEM 223 or 237 sequence; check department websites and contact department advisers for recommendations. The CHEM 335 sequence is taken by strong science students looking for a challenging course, and is always accepted in place of the 223 or 237 sequence.
Prerequisites
There are two special points about chemistry prerequisites:
- Not only must you take the prerequisite course, but you must achieve a minimum grade of 1.7.
- Because you register for next quarter before you've finished this quarter's classes, you're allowed to register for the next course in the sequence while you have the prerequisite in progress. If you don't complete the prerequisite with the required grade, however, your registration in the next course will be cancelled.
Example: You must achieve at least a 1.7 grade in CHEM 142 to continue on to CHEM 152. If you register to take CHEM 142 in autumn quarter you'll be allowed to register for CHEM 152 in winter quarter, but if you receive a grade of 1.2 in CHEM 142 your registration in CHEM 152 will be cancelled and you'll be removed from the course. You must repeat CHEM 142 and earn a higher grade to qualify to take CHEM 152 in a later quarter.
Placement Tests
A placement test is required only for CHEM 145. Students with a score of 4 or 5 on the AP Chemistry exam, or a 5, 6, or 7 on the IB (Higher Level) exam, are not required to take the placement test. For the test schedule see the Testing Center website.
AP and IB scores
Students with scores of 4 or 5 on the AP Chemistry exam receive credit for courses in the CHEM 142 sequence. See our AP tables for the specific credit awards.
Students with AP scores of 4 or 5 are strongly encouraged to take the CHEM 145 sequence. Students who do so will, however, lose the AP credit because credit is not allowed for both the 142 and 145 sequences.
UW does not award credit for the International Baccalaureate Chemistry exam. Students with a score of 6, however, may skip CHEM 142 and start with CHEM 152. Students with a score of 7 may skip CHEM 142 and 152, and start with CHEM 162. As with AP scores, we strongly recommend that students take the CHEM 145 sequence instead of skipping courses.
Chemistry Labs
CHEM 120, 220, 221, and the CHEM 142 and 145 sequences all include both a lecture and a laboratory in each course. Each schedule line number in the time schedule corresponds to one lecture/lab combination.
The labs that accompany the CHEM 223, 237, and 335 sequences, however, are separate courses. Some majors require the labs and some don't, although almost all majors at least recommend the labs. The prerequisite to the labs is the first quarter of the lecture series, so the labs are generally taken with the second and third quarters of lecture. Students taking the CHEM 223 and 237 sequences take the labs 241 and 242. Student taking the honors 335 sequence usually take the honors labs 346 and 347. CHEM 241 and 242 are offered most (but not all) quarters, and are available evenings in winter and spring quarters. CHEM 346 and 347 are offered only in winter and spring quarters.
All chemistry lab courses require a separate lab fee, which will be included in your tuition bill.
Chemistry Transfer Credit
If your chemistry courses transferred as direct equivalents — they are posted as CHEM 142, etc. — then (assuming you have the minimum prerequisite grade) you may register for the next course in the sequence. If your courses transferred as "X credit" — CHEM 1XX, etc. — you need to speak with a chemistry department adviser to determine which course you should take next. Contact the chemistry advising office for an appointment.
If you are enrolled in chemistry courses at another college and planning to transfer to the UW, we strongly encourage you to finish your chemistry sequence before transferring. The topics are seldom taught in exactly the same order at different colleges, and if you transfer mid-sequence you may miss some topics and duplicate others.
The transfer equivalencies for courses taken at Washington community colleges are listed in the Equivalency Guide.


