The student clearly stated the independent variable, which was the concentration of NaOH, and the dependent variable, the temperature change during the neutralization reaction with HCl, in the research question. The student effectively described the method of analysis using calorimetry and provided relevant background theory on the neutralization reaction, including key thermodynamic concepts. The choice of techniques for measuring the variables was clearly explained; however, the student did not specify the sampling technique used to select the NaOH concentrations, which would have enhanced the reliability and validity of the investigation. The student adequately discussed the number of trials, controlled variables, safety, ethical, and environmental issues, and presented a detailed methodology that allowed for reproducibility without irrelevant information.
