Can one course count for both General Education credit and for credit within my Sociology Major?
This is often the case. Often, but not always. For example, Soc280 counts as General Education credit. It can also count as one of your electives within the Sociology Major, however; there is a limit to the number of 200 level courses that can count toward your major. If you have exceeded that limit then Soc280 would satisfy only the General Education requirement.