pH Measurement and Modelling as a Link between High School Chemistry and Mathematics

Abstract

Investigating the acidity and alkalinity of solutions is linked to understanding the pH of solutions. At the secondary school level, this also means understanding the concept of the logarithmic function, which is a suitable topic for developing mathematical literacy. The objective was to design a laboratory activity in which students would not only measure solutions with the expected pH, but also construct a graph from the measured values without being aware of the dependence of pH on H₃O⁺ concentration. This would enable them to identify the function that best fits the obtained curve. The problem presented discusses the limitations of the design and provides teachers with a basis for preparing the laboratory exercise, including a worksheet for students. The validation of the laboratory activity demonstrates that during the implementation of the exercise, students are able to construct a graph from the measured values and solve application problems related to understanding the concept of a logarithmic function.