Where do I even start? Barr is a terrible professor: he seems to be caring and concerned about our learning at first but after a while it all goes to shit. He is pretentious and has no good intentions in teaching. His teaching philosophy emphasizes collaboration, and while this approach isn't harmful to us, it should not be mandated for COLLEGE STUDENTS. Students are in a constant state of confusion and making us work together just makes us more confused.

The discrepancy between his lecture material and exam content is the reason we struggle. The material in CHEM 20B is not exactly easy but a good amount of effort should result in a decent grade. Not in Barr's class though. He is a decent lecturer and explains concepts with example questions. HOWEVER, his exams are not reflective of the course material and he expects us to understand these "higher level concepts" that he barely explains in class. He does have a group portion for the midterm which helps your grade slightly.

There are a lot of things I dislike about Barr, but the one thing that I hate about Barr is how he refuses to release answer keys for his problem sets, homework, and practice midterms. He claims that solutions would not benefit our learning, but that's just gatekeeping... It's really frustrating and it just shows how indifferent he is when it comes to students' success.

OVERALL: this class isn't impossible, but you will keep questioning yourself the whole quarter. Go to office hours because he usually goes over problem-set questions. This class is poorly designed and I DO NOT recommend it. Barr needs to start taking student feedback as a professional. I hope he realizes his flaws more than he boasts about his strengths. Good luck to those of you taking Barr.

This class is not hard to get a good grade in, but it's very frustrating for those who actually want to understand the material. Lectures seem to jump around and unevenly emphasize content, though I appreciated the recaps. We either spent too much time on complicated derivations or extremely basic problems, rather than the applications more suited to an introductory-level class. Many generous policies made up for the resulting poor performance.

this class made me switch my major (biochem) LMAOOO to be fair, i did not put in enough time for the class, but even then, there is sooo much content that you'd have to have a prior chemistry background to fully understand what he goes over.

you don't really have a choice if you're in stem, and must take this course, so my biggest advice: throw away ur social life and grind chem!! jk. but fr go to office hours bruh

For it being his first time teaching, Barr was decent. He's very enthusiastic, passionate, and invested in our learning which is nice having a professor that cares. Also, he provides a lot of resources for practicing the material and provides students with opportunities to get help in terms of office hours, campuswire, review sessions, and being open to questions during lectures. He's quite helpful when you ask him questions directly through audio and patiently and thoroughly explains the concept until you understand it to your satisfaction.
A lot of the negativity towards him comes from his insanely difficult midterms, which is fair as they are very difficult. However, his final, which was still challenging, was significantly easier than the midterms and has a much greater affect on your overall grade, giving you a chance to improve you grade significantly even if you did poorly on both midterms. Nevertheless, you do need to put in a lot of work for the class, as there is a lot of material to learn, understand, and master. It is quite a difficult course which can be a little disheartening at times but you definitely learn a LOT and in the end it works out better than expected.

To the person who said this is fuckin UCLA and if you can’t handle this course you’re going to die in your future classes”.... you’re a fucking asshole. Keep to yourself and sit down.

The class itself was fine, but Barr made it a lot worse than it had to be. He doesn't ever explicitly say what he expects from students. His tests were sometimes loosely connected to the material and students would have to guess compounds and names that were never shown in class. This class could use some help in terms of logistics, and the majority of the students had a hard time enjoying it.

i switched out of my chemistry major after taking this class

This class is honestly one of the worst classes I have taken at UCLA. The quarter started off ok, but you soon realize that reading the textbook will not help you on the exams. He barely covers the material you need to know in lecture and the only way to try similar problems to the exams were to work his optional practice problems that he NEVER released the solutions to. Literally the only way to figure out how to do these problems were to go to the professor's office hours as sometimes even the TAs couldn't figure them out. His zoom office hours no joke had 100+ people sometimes. Overall, he acts like he sympathizes with his students, which makes it even worse when he absolutely destroys the class with exams. Avoid taking this class with Barr at all costs.

Worst teacher I’ve probably ever had, confusing overly fast-paced lectures, unnecessarily difficult tests. If you’re only option is Barr, just don’t take the class

I think Barr is passionate, but my experience with him was terrible. The exams were tough, and he would not listen to class feedback. To be honest winter quarter was just a nightmare all over. The whole class experience was akin to experiencing a firebombing 24/7. That said, I understand it was his first time. I just wouldn't take him again. UCLA Chem department needs to do better, as their restrictions during covid probably was also terrible and made it harder for Barr to accommodate us. I heard he got better, so take my review as you will. I just can't say he was a good professor based upon my experience.