Simulation-Based Guided Inquiry Activity for Deriving the Beer–Lambert Law

Abstract

The Beer–Lambert law is a core spectroscopic relationship widely used across the undergraduate chemistry curriculum and beyond. The derivation of this model is a common topic for upper-level chemistry courses. But, due to its abstract nature, this derivation can often seem like a mathematical exercise detached from the molecular origins of absorption. Here, we present an activity centered around a simulation of absorption using spheres and cylinders. By interacting with variables in the simulation in a guided-inquiry format, students can connect the submicroscopic interactions between photons and molecules with the mathematical relationships that ultimately give rise to the Beer–Lambert Law. The activity presented here was implemented as a virtual lab for a cohort of analytical chemistry students during the COVID-19 pandemic. Our evaluation of student responses shows the promise of this activity for encouraging students to engage in the scientific practice of modeling the submicroscopic nature of absorption to understand the development of Beer’s Law. In addition, we discuss how patterns observed in student responses have informed improvements to the activity for future implementations and identify some additional learning contexts to which the interactive simulation can be applied.