An initial sample of 94 students enrolled in a first-term general chemistry course was tested with paired algorithmic–conceptual questions, which included questions first used by Nurrenbern and Pickering. The topics of these questions were density, stoichiometry, gas laws, and molarity. Scientific reasoning skill was measured with the Classroom Test of Scientific Reasoning. The skills assessed by this instrument are conservation of weight, conservation of displaced volume, proportional thinking, identification and control of variables, probabilistic thinking, correlational thinking, and hypothetico-deductive reasoning. Results showed that success on algorithmic questions was always higher than on conceptual questions, verifying the results of previous studies. Additionally, the students with better reasoning ability outperformed students with poorer reasoning ability on all question types, and the scores of the better reasoners were significantly higher than those of the poorer reasoners on three of the four conceptual questions administered, as well as on the ACS final examination. The results indicate that variation in scientific reasoning skills is one cause of the gap between algorithmic and conceptual problem-solving ability.