This study investigates the potential of five factors that may be predictive of success in college general chemistry courses: prior knowledge of common alternate conceptions, intelligence, scientific reasoning ability, proportional reasoning ability, and attitude toward chemistry. We found that both prior knowledge and scientific reasoning ability were significantly correlated with students' performance on the American Chemical Society Division of Chemical Education Examinations Institute First Term General Chemistry Examination. Given that scientific reasoning ability was significantly correlated with final exam performance and that its impact is not broadly known in the chemistry teaching community, we then discuss the implications for facilitating the development of reasoning ability in college preparatory high school chemistry courses and college preparatory chemistry courses.