Lightning in a Bottle: Measuring NOx Formed by Electrical Discharge in an Inquiry-Based General Chemistry Laboratory Experiment

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 19 (2014) pp 305-309

Lightning in a Bottle: Measuring NO_x Formed by Electrical Discharge in an Inquiry-Based General Chemistry Laboratory Experiment

Kurt Winkelmann*, Monica H. Baloga, and Alfred Menendez

Department of Chemistry, Florida Institute of Technology, 150 West University Blvd, Melbourne, FL 32901, kwinkel@fit.edu
Received May 19, 2014. Accepted September 27, 2014.

Published: 10 October 2014

Abstract. Students in general chemistry laboratory investigate the formation of nitrogen oxides (NO_x) gases produced by electrical discharge under different experimental conditions. In the first week of this three-week laboratory experiment, students generate NO_x gases using the electrical discharge of a Tesla coil to break down N₂ and O₂ in air. After mixing the reacted sample of gas with an aqueous indicator solution, they quantify the concentration of NO_x using spectrophotometric techniques. They select a research question related to the experiment to investigate during the next two laboratory sessions and develop a hypothesis. Based on skills learned during the first week, students design their own experimental procedure, interpret their data, and report an appropriate conclusion. This inquiry experiment introduces students to traditional chemistry topics (e.g., gas laws, dilutions and oxidation-reduction reactions) as well as applications of chemistry such as lightning and atmospheric science.

Key Words: Laboratories and Demonstrations; general chemistry; atmospheric chemistry; inquiry; formation of NOx gases

(*) Corresponding author. (E-mail: kwinkel@fit.edu)

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Supporting Materials:

Supporting materials for this article include (1) the laboratory handout containing background, procedure, research questions and supplementary information for students, (2) the spreadsheet used to graph data and calculate NO_x concentrations and (3) instructions for preparing solutions used in this experiment (285 KB).