As a EE, and a general rule if you put in 40 hours or more a week studying, and some will, you will generally have a very good GPA, if you put in 10 hours a week, well you better be brilliant or you’ll probably have something less than a 3.0. The more work that you put into your studies/job/hobby the better the outcome, you might try reading “outliers” and the 10000 hour rule.
^^ I’m not sure that’s always the case, though. Check this article out (but ignore the headline; it’s misleading):
https://www.wsj.com/articles/the-smarter-ways-to-study-1502810531
Regardless, you better prepared to work harder than you did in high school if you want a high GPA in chemical (or any other) engineering major.