Overall Johnny is an excellent professor. For this class, as long as you put in the busy work and some slight studying, there's no reason to not be able to get an A.
Lectures are quite engaging, and despite his quick talking and slight accent, you'll have no problem understanding him whatsoever. Everything is very easy to follow; he prints the slides out on paper for all the students, and you can follow along and mark up wherever needed. He's often quite funny, and uses some very childlike animations to describe certain concepts, so definitely don't miss it! Also, during one of the lectures, he gave all of us glowsticks (complementary gifts for everyone), so his lectures are quite entertaining. He's very straightforward and very concise about what he's teaching, and you never feel like there''s something he hasn't explained properly.
The labs are honestly a lot of busy work and a big suck on your time, but nothing else. Going to office hours for these really help, since the TAs are the ones that grade your labs, so make sure you are doing them correctly and hitting their explanations! If you regularly go to office hours, there's no reason not to be able to get nearly all if not all of the lab points for this course. The experiments themselves are quite tedious however, you will learn to hate the word "titration" by the end of the course, as those experiments are typically the longest since messing up means redoing the titration again. Also, nearly half of the experiments are group experiments, so it's not as bad as it could be.
The exams (one midterm, one final) are very strict about the grading! There's a specific answer key, that gives the TAs no leeway to grade differently, so if you are banking on influencing your TA to grade more leniently, that won't work here (I know some people who do do this however). Focus on significant figures and explaining everything clearly, as the rubric is very specific about making sure you hit those marks. This is probably where you lose the most points (I certainly did in this department; I got a C on the midterm because of it, but the average was around an 85% so don't worry about the difficulty), but conceptually, the problems themselves are not the most difficult; just study from the study guide that he posts. The final was all multiple choice (out of 180 points but scaled to 150), so that was extremely easy (or hard, if you hate multiple choice). I definitely feel like I guessed on some of those problems, but because of the grading scheme (straight scale out of 450 points, with the final 150 and the midterm 50) I was still able to snag out an A, so it's definitely doable for you to do well in this course! Also, for what it's worth, after the quarter Pang sent out an email stating that the final average was a 73%, but more importantly, the overall class average was an 87%, and 50% of people got some form of an A, which is a pretty darn good deal if you ask him. Cool dude, snazzy lecturer, and would definitely take the guy again if possible. highly recommend.

The lab portion of this class was very easy to follow and the labs were somewhat interesting. The lab report grading seemed fair, with a heavy emphasis on sig figs. The midterm was also heavily graded on sig figs and other computations. Personally, I found the tests very challenging. I don't know if other people just found them easier, or maybe I didn't study enough for them, but I had a really hard time remembering all the rules and nuances for different experiments and problems. Overall, this was a pretty good lab class, but definitely pay attention to what Pang says, even if it doesn't seem like it matters to the lab that you're doing, because some of the smaller details seem to reappear on the tests. He did provide a very lengthy study guide, but I thought it was too long and given to us too late to be fully completed and understood.

Pang is a GREAT professor. Everything is laid out to you clearly. He’s funny. He’s personable and comes in to labs to check on you and make sure you understand everything. He does everything to make sure you understand the material. 10/10 would take his class again even though I got a B

The best Chem professor at UCLA. Just do the work and should get an easy A nothing is too hard at all. Only bad thing have to buy lab coat, manual, and $50 notebook for the class. (can go to either lecture if he is teaching two sections)

Labs - read lab manual before going and always ask TA for help if don't know what to do next. For some labs need a steady hand such as in titration so move slowly and carefully and will still finish the lab over an hour early plenty of time, grade from pre-lab and post-lab but his online instruction so clear so get 100% every time

Online writing - Only one 300 words essay follow the direction which are very clear and include all parts should be easy A (plus if you do well he will give you extra credit on midterm)

Midterm (only one) all computational if you do all the problems one the study guide he posted you should get a 100%, don't need to reread labs and stuff just do problems

Final - Does not tell you but will be mostly multiple choice, when studying focus on concepts and reread lab procedures to do well on multiple choice section which is the majority of it. As with midterm to practice problems he posts on study guide

Excellent professor with a great sense of humor (HA HA HA... if you took his Winter 2019 class, you’d get the joke). Lectures were vague, but it wasn’t his fault because class only meets for an hour every week. Some labs were interesting, while others are a pain to do. Lab reports took forever, and the final was very hard compared to the midterm. Overall, I’d recommend this professor, and you will definitely learn a lot from him.

Dr. Pang was an excellent professor for Chem 20L. He has taught this class a number of times now, and has everything down to a science. He has all of his materials well organized, and has plenty of office hours to help students individually should they have further questions. Here's some tips if you are taking him in the future:

-Do the study guides before exams, they help prepare you well for them.
-Before the final, also make sure to review the experiments and set ups. The final is significantly trickier than the midterm.
-I personally didn't do the practice problems/supplementary readings and didn't find it necessary, however if you are struggling feel free to look them over.
-Check your pre-lab study questions for sig figs with friends before turning it into the TA

Dr. Pang is as great as everyone says he is. He is is an excellent lecturer, is extremely organized, and sets clear expectations for the class. However, don't equate that with an easy A. This class is graded on a strict points system, so you can only miss about 46 points total (out of 465) to get an A. Lab materials are graded strictly, so you need to make sure that you completed everything nearly perfectly.

Some tips for success:
-Form a group chat and check all of your lab report answers. Try not to miss easy points because you want a solid 20-30 point buffer going into the final.
-Don't procrastinate. You'll make more mistakes doing your labs late at night.
-Do the practice study guides.

Overall, getting an A in this class is very achievable. Just go to lecture, don't lose too many points, and don't underestimate the midterm and final.

The professor, hands down, is an awesome professor. His lectures are clear and engaging, and his office hours are very helpful.
The labs themselves are not to difficult; pay attention to sig figs and the directions and you should get a good grade for them. The midterm and final are trippy, however. They focus on the conceptual stuff. Fortunately, the writing assignment is very easy, and gives a lot of extra credit.
The workload was significant, however.

Super easy and fun class, overall. Some of the labs weren't super engaging, but Dr. Pang made the class as painless as it could be. Dr. Pang is a wonderful, approachable lecturer, and I would highly recommend taking 20L with him.

Professor Pang is a godsend. Really good, clear, and concise lectures -- and he prints out note packets for each for you to fill in key points. He's also really accommodating and clearly cares about his students. 11/10.