The student clearly states the independent variable as the concentration of MgCl₂(aq) and the dependent variable as the amount of caffeine extracted from coffee grounds. The research question includes a detailed description of the method of analysis, specifically mentioning UV-Vis spectrophotometry at 277.0 nm for measurement. The background theory is well-articulated, connecting relevant concepts to the research question, while the choice of techniques for measurement is justified, showcasing a systematic approach to the investigation. The student effectively addresses controlled variables, safety, ethical, and environmental considerations, although the methodology lacks some specific details needed for reproducibility. Overall, the methodology is presented clearly without irrelevant information, allowing for a solid understanding of the experimental design.
