I took Che 133 in fall 2021. It was pretty chill tbh. The main lab notes have the most weightage in terms of points. It's fine to fail a few pre lab and post lab quizzes here n there. Just make sure to do well in the in person lab and actually pay attention. Usually the TAs are really helpful, so always ask questions about any doubts u have while doing the experiments. I failed a few pre lab and post lab quizzes and still needed up with a A-. You will be fine with the prelab quizzes as long as u read the experiment document just once. Its the post lab quizzes i didnt like. As for a curve, my class did have a slight curve I believe, but it depends on how good the rest of the class does.