The study aims to demonstrate evidence of (a) students' conceptual change on solution rates; (b) students' sub-microscopic explanations of dissolution; and (c) retention of the concepts of solution rates. The sample consists of 44 Grade 9 students (18 boys and 26 girls) drawn purposively from two different classes (22 each) in the city of Trabzon, Turkey. The current study incorporates multiple methods of data collection: items from a solution concept test, clinical interviews and examination of students' self-assessment tasks. The results reveal that there is a statistically significant difference between scores in pre-test and post-test and between pre-test and delayed test (p less than 0.05). This research indicates that the intervention has improved students' understanding of the conceptual relationship between solution rates and the sub-microscopic explanation of dissolution. It has also helped in overcoming students' alternative conceptions to some extent. However, alternative conceptions have not been eliminated completely. In the light of the results, this current study suggests that a simple model such as the four-step constructivist teaching (4E) is efficient. (Contains 6 tables and 1 figure.)