I numbered your pieces and here's my opinion about them. Use wear analysis would tell you what they had been used for, but without seeing them I'm only guessing.
MATERIAL
1,2,3,4,5 are all pieces of burlington chert. There are out croppings of burlington chert in the bluffs along the mississippi and illinois river in the area.
6 & 7 look alot like Cobden / Dongala Chert but I think it's something else, but I'll get to that in a moment. Cobden / Dongala is found as nodules in southern Illinois, but is found in our area (madison county) used primarily during the Middle Woodland and Mississippian periods. Personally I think it could be some of the Nodular chert that occurs in the bluffs above the Pierre Marquette visitors center. I believe it to be nodular St Louis green chert, but unfortunately I knapped the few nodules I had years ago.
USAGE
1 A broken biface perhaps. Bifaces were a stage in reducing a hunk of chert to a blade or projectile point. They often were utilized as tools never reaching or having been intended to reach final form as a knife or projectile point. Lacking alot of secondary flaking or edge wear, I suspect yours broke while being knapped.
2 Interesting piece appears to me to have been ground on the one edge. May have been an Archaic period blade or point.
3 A piece of chert. Might have some retouch or use damage on the left hand side in the picture, suggesting it have have been used as a tool.
4 A chuck of chert, may be an exhausted core. Appears to have been utlized as a tool, most likely a knife for cutting or scraping.
5 Another chunk of chert, but most likely used as a core as it's possible to see a flake scar runing down the face of the piece. Again likely used as a tool.
6 Weathered piece of chert, with no signs of usage apparent.
7 Exhausted core. Likely a highly knappable piece of chert as it was reduced to such a small size that one could only obtain small bladelets from it.
8. Not a clue. A sedimentary rock. I've seen abraders used to sharpen bone tools made from similar materials, but I can only assume it's only a rock and not an artifact.
CONCLUSION
I assume these artifacts are likely from a site that was occupied during the late archaic to early woodland period. Archaic people of our area tended to move from site to site frequently. Over the years a single site could be occupied many times. If you find any complete or nearly complete points (arrowheads) I can give you a better estimate as to when the site was occupied.
Mike