Ozone measurement practice in the laboratory using Schönbein's method

Abstract

We present a laboratory technique to measure tropospheric ozone, following a traditional method developed by Christian Friedrich Schönbein in the 19th century. The aim is to familiarise students with both the scientific method and the concepts of pollution and climate change, taking advantage of the possibilities of a very cheap hands-on approach over other existing theoretical ones. Also, this teaching activity can help the students to understand the differences between objective and subjective analysis. Moreover, they can make effective use of new technologies and photography. We include a description of how to conduct the lesson at two different levels of complexity (advanced and basic) to allow us to adapt it to the capacity of the students. The advanced level includes the production in the lab of paper strips as they were produced in the 19th century, whilst the basic level does not. This practice is suitable for use by both high school and first-year undergraduate students and was presented in high schools during a communication campaign to celebrate the annual Galician Scientist Day. We evaluate the teaching approach used through the results from collected surveys and feedback received from the students and teachers.