Lecture 09: Graphical Solutions (Chapter 2)

LECTURE OVERVIEW: In this lecture, we explore graphical methods for solving acid-base speciation problems, focusing on constructing and interpreting pC-pH diagrams. We begin by outlining how these diagrams can be used to calculate the pH of a solution and understand the concentrations of species at different pH levels. The lecture covers the construction of pC-pH diagrams for monoprotic acids and expands this method to polyprotic acids, demonstrating how to graphically solve for the pH and evaluate species concentrations in more complex systems. INTENDED LEARNING OUTCOMES: By the end of the lecture, you will be able to: • Construct pC-pH diagram • Solve for the solution pH using the pC-pH diagram • Expand the constructed diagram for polyprotic acids RELEVANT READINGS: • Water Chemistry, 2nd Edition, by Mark M. Benjamin 6. Acids and Bases, Part 2 6.1. Graphical Solutions for Sets of Simultaneous Equations 6.2. Using LogC-pH Diagrams to Solve Weak Acid/Base Problems --------------------------------------------------------------------------------------------------------------------------------- COURSE INFORMATION: This video is part of the Environmental Chemistry course, designed and taught by Prof. Mim Rahimi. The course covers the following chapters: (1) Fundamentals of Environmental Chemistry, (2) Acids and Bases and Related Phenomena, (3) Chemistry of Metals, and (4) Redox Chemistry in Environmental Systems. COURSE REFERENCES: The recommended textbooks for the course are: • Main Reference: Water Chemistry, 2nd Edition, by Mark M. Benjamin, Waveland Press Inc., ISBN: 978-1478623083 • Additional Useful Reference: Environmental Chemistry, 10th Edition, by Stanley E. Manahan, CRC Press, ISBN: 978-1032339726