AP Chem is 2 periods all year at my school, and AP Comp.Sci & H.Chem is 1 period each (2 periods total) all year long.
What would be easier?
It depends on your school. Also, for APCS, do you have any experience? At my school, the course is absurdly hard for anybody with only a little experience, but that’s also because the people setting the curves have developed apps and stuff. AP Chem is generally a difficult course, but I don’t know how it is at your school. Better to ask someone at your school who has taken the courses about the relative difficulties.
I do have some HTML, C#, and Java experience. How about H.Chem?
H. Chem really depends on the teacher. At our school, the material isn’t very hard, but the teachers are either a) death, or b) death, for a different reason (aka weird homework). It also depends on how good you are at science–obviously AP Chem goes far, far more in-depth, but it can be difficult to understand Honors Chem material if you’re not generally a science person. If you are, chemistry is pretty easy; if you aren’t, it’s hard.
Honestly, I would go for AP Comp Sci & H. Chem if Comp Sci is something that is interesting to you. If it’s not then take AP Chem. what sciences have you already taken?