The man is cool to talk to but thats about it. I found it difficult to understand the material with him as the professor. At the beginning of the quarter he explained, "How does one succeed in my class." Let me tell you, I did everything he asked for and still got a D on both midterms(individually at least , there is also a group portion that acts like a "curve"). I kid you not, I have no idea how I got an A- because i thought i was going to get a C+ or B- best case scenario. I think I must've done really well on the final(doing better on the final exempts one of your midterm grades). At the end of the day, this class is not worth the headache and stress. Find a different professor.

It's clear Barr is excited about teaching and his lectures are well put together, but the structure of his class is a little annoying and difficult at times. The worst aspect is that there are no answer keys to anything, so you need to make time for office hours if you want to check your work, and even the TAs don't often understand the problems he writes. The midterms were challenging and the wording of the questions made it even harder. The final was much more straightforward and there were a lot of opportunities for credit in other areas besides the tests (homework, discussion, etc).
Making time to go to office hours and completing his problem sets early so you can study from them makes this class doable.

I did not like this class. I think most people in engineering or similar majors will have to go through this, and it seems as if Barr is the only option. I'm sure you see all of the other reviews and I would likely agree with most of them. Unfortunately, this might just be the hazing for engineers that we don't get otherwise. Some people would say go to office hours or do the problem sets, but I'm really not sure how much my studying was worth it for the exams. If you want to do well in this class, I recommend not taking a difficult load and studying 10+ hours a week and also have a passion for chemistry and hopefully have taken AP Chem and gotten a 5.

Enjoyed it. He gave tons of partial credits and extra credits on his exams which made them not as stressful. I almost cried trying to read the textbook, and I honestly don't think it's helpful at all. You don't need to understand everything that's on his problem sets. Go to his lectures and maybe his office hours if you're not sure about something.