so from your posts I get the impression that going to a phD school is mostly, if not all research. How many classes/credits do you have to take? And also on average how long does it take to get a phD after 4 years of undergrad? Furthermore, how much is the average phD tuition?
Well, unless you have really convinced the graduate department, they will make you go through the basic classes on your way towards a Masters Degree. Depending on the situation, and how many of those classes they make you take, but, even if they made you do everything required for a MS it would take you only two years to complete those. After that, yes it is pretty much all research; your own and you being the gofer of other faculty members.
At the minimum of going straight from BS towards a PHD they would make you take at least 3 of the 4 basic masters level core chemistry classes (one organic, analytical, inorganic and physical chemistry); I would imagine.
There are a few difference in the general outline for schools in the USA or say in Europe, when it comes to graduate level.
As for the time, it takes some people not long and some people really long.
As for tuition, in the hard science, especially chemistry with it being such a core science important to every major industry, you rarely have to pay tuition. You tuition is paid and you usually get a stipend. You also can get in on grant money, and if you are helping some other professor with their work, they sponsor you with some of their grant money (this is in part what the grant money is actually for).
Maybe the first semester or two, or if it is a really big school you will have to pay. But the cost is totally dependent on the area and school. I could easily find you graduate programs with 1/4th the price of some undergraduate programs.
It is usually not that hard to get a stipend and tuition paid (well, not in the parts of the US I have ever lived and know people attending graduate schools). Many schools will require you to be a TA or teach a freshman lab, etc. to qualify for the stipend though.