The student demonstrated a strong understanding of the subject by accurately using relevant terms and concepts throughout the essay, particularly in their detailed explanation of the saponification process and the role of refluxing. They effectively discussed relevant processes and theories, incorporating terminology such as "nucleophilic attack" and "ester linkage," which reflected their knowledge of chemistry. The essay was relevant to the research question on how different oils affected soap production and pH levels, and was supported by a variety of high-quality sources. However, the student needed to further explore the topic by providing more comprehensive details about the apparatus, chemicals, and procedures used in the experiment to strengthen their research.