Long ago, I got a D in my first semester of General Chemistry, retook it and got a B. The second semester I got a C... essentially this could be interpreted as a C both semesters. I have since completed Organic Chemistry and Biochemistry with much better grades, and revised enough General Chemistry material that I became proficient enough to tutor the subject for a few semesters; I will be attending dental school next fall.
Point being, the C's may not look the greatest, but if an Admissions Committee can see improvement in some form (possibly by rocking your upper-level chem courses, and/or killing the DAT chem sections) they would probably be willing to overlook those grades. 🙂