“…This is because this material requires an understanding of concepts, mastery of related prerequisite material, abstract formulas, and applications into mathematical calculations to solve problems (Nomilasari, 2019;Hesti, et al, 2019;Fitriani, et al, 2019). Viyandari, et al (2012), Ulfah, et al (2016), andSudiana, et al (2019) state that the factors that cause students difficulty in learning the solubility material and the solubility product constant can be derived from internal and external factors. Internal factors, such as interest and motivation to learn chemistry are low, the meaning of students' concepts of material and prerequisite material is low, students' ability in mathematical operations is weak, students' inability to associate their knowledge and experience with actual concepts or scientific concepts.…”