Facilitating student understanding of buffering by an integration of mathematics and chemical concepts

Abstract

We describe a simple undergraduate exercise involving the titration of a weak acid by a strong base using a pH meter and a micropipette. Students then use their data and carry out graphical analyses with a spreadsheet. The analyses involve using mathematical concepts such as first-derivative and semi-log plots and provide an opportunity for collaboration between biochemistry and mathematics instructors. By focusing on titration data, rather than the titration process, and using a variety of graphical transformations, we believe that students achieve a deeper understanding of the concept of buffering.

Small Changes: Using Assessment to Direct Instructional Practices in Large-Enrollment Biochemistry Courses

“…Meaningful understanding of pK a is very important to learning biological concepts and in applying this knowledge to contexts such as buffers and electrophoresis ( Moore, 1985 ; Curtright et al. , 2004 ; Orgill and Sutherland, 2008 ).…”

Student understanding of pH: “i don't know what the log actually is, i only know where the button is on my calculator”

“…A review of the educational literature reveals that there is limited research addressing student understanding of pH and related issues. The focus of much of the existing research has been on the use of strategies to learn the concept [8] or practical activities using titration exercises to provide concrete graphic models to achieve a better understanding of buffering [9]. What limited research exists suggests that students' overall comprehension level of key acid/base principles is so deficient that students cannot use pH concepts effectively to solve problems [10].…”

“…The focus of much of the existing research has been on the use of strategies to learn the concept [8] or practical activities using titration exercises to provide concrete graphic models to achieve a better understanding of buffering [9]. What limited research ex- ¶ To whom correspondence should be addressed.…”

Using PyMOL to Explore the Effects of pH on Noncovalent Interactions between Immunoglobulin G and Protein A: A Guided‐Inquiry Biochemistry Activity

“…Students depend heavily on symbolic manipulation of mathematical concepts to communicate their understanding of pH and p K a . Previously published exercises on acids and bases seek to assist students with connecting the mathematics to the chemical concepts and research suggests that biochemistry curricula need to provide students with opportunities to integrate these important concepts .…”