How many times do I have to put substance x in a graduated cylinder for it not to dissolve anymore?
You are only allowed to ask one question at a time so I had to edit down. Your question is somewhat vague. If I am to assume that you are putting a solid (substance x) into a graduated cylinder filled with a liquid solvent like water until it does not dissolve anymore, then the answer will vary greatly and depend on exactly what substance x is and what solvent you are using (and other factors like temperature). When adding a polar solid like a salt to a polar solvent like water, the solid will dissolve with some stirring or agitation. When the solvent has reached the point where it simply cannot dissolve any more solid, the solution has reached what is called the saturation point. So you will have to add enough substance x for the resulting solution to become saturated before it will not dissolve anymore.