I'm a first-year graduate student, and I just joined a computational chemistry laboratory. I have three tasks now: pass all my courses, fulfill my TA duties, and start research. I'm finding that I'm spending all my time doing the first two, and very little doing actual research. I'm worried that my advisor will be upset that I'm not getting up to speed quickly enough on my research (currently, learning the python programming language and reading a whole bunch of papers). Are first-year graduate students typically expected to do a lot of research, while still managing their grades and TA duties?
I think the answer lies in what your PI thinks you should be doing and how well you can, at least, appear to be doing it while doing things other than research. Even if your PI doesn't enforce a certain allocation it's in your interest to do as much research and little else as possible. You won't get a PhD by teaching or taking classes. An overload, in my experience, is unavoidable first year. Is is possible to take electives that your PI teaches? That's about the only coursework he or she won't begrudge you.
A lack of time for research in the first year is pretty common in programs with heavy course requirements, and your supervisor will usually know this especially if she or he has other students. I used to tell my supervisor that I was pretty busy with courses and this was no problem, and I doubt your advisor will get upset if you also have this issue.
On the other hand, I like the comment of DNA. You'd be surprised that even with a busy schedule there is a lot of room for improvement in how you manage your time. If you take a bit of time to examine your schedule, possibly with the aide of a spreadsheet, often you can find ways to improve your efficiency. Courses and TA duties are tiring and it is difficult to work after them. If this is your case you could try getting up earlier to have the best part of your day for a bit of research. Even three hours per week per semester will be around 40 hours in a semester, depending on the semester length, and you can accomplish much in this time.
I think it's fair to expect a first-year student who has course obligations to spend some time on course work, but along the same lines as if it were another course—and by no means the majority of time. When the department requires coursework, it's kind of unfair for a faculty advisor to complain about you having to spend your time taking the required classwork. Particularly in a department like chemistry, which tends to have comprehensive qualification requirements, expecting a first-year student to devote more than a modest amount of time to research is rather unreasonable. If you spend too much time on research, and not enough on classes, you could end up failing your qualfiers. If you don't pass those, you won't get your Ph.D., either!
In France coursework is anecdotal since PhD students are supposed to follow only one course a year, and the validation is decided (without grades) by the professor giving the lecture (and attendance generally means validation).
However, the question of balancing research and teaching is of importance. Those that are TA during their PhD have typically 3 to 4 hours a week on average of presence in front of the students during 6/7 months, and most colleagues agree on the fact that 2 to 3 times this amount is spent in preparing/grading (for beginners). So it is on average between 1 and 2 days a week for teaching. I strongly advised my own students not to cross that line: you don't improve significantly your lectures by working more than that, but you clearly decrease the quality of your research work (again, this is for newcomers in academia).
From my experience: You just have to make it work. You just have to balance all that is thrown at you. Believe me, it is a character building exercise, getting a PhD is. It's not just about publishing journal papers. A PhD degree is also about time management, people skills (which can be tested when trying to appease your advisor!) and learning how to communicate effectively (even if you get only 10 hours work done in a week while the expectation was 15 hours, it is how you communicate your results during research meetings).
After a year or so and once you have your qualifiers out of the way you will emerge a stronger person who would suddenly even have downtime! Good luck!