The COVID-19 pandemic resulted in an unprecedented number of students taking general chemistry lab courses remotely. At our institution, during the 2020-2021 academic year we made the decision to send laboratory kits to our remote general chemistry lab students, aiming to give students the most realistic lab experience possible at home. Ultimately, 110 General Chemistry I students and 70 General Chemistry II students enrolled in our remote laboratory courses, and every student received a lab kit to use during their semester of live instruction via videoconference. We estimate that kits cost around $100 per student, not including the $15-80 cost to ship each kit. In addition, we paid for return shipping at the end of Fall 2020 to recover materials for the following semester.

We were able to cover the bulk of the traditional general chemistry curriculum in our remote laboratory classes. With the first-semester laboratory kit, students explored scientific measurement, created calibration curves two different ways, measured the absorbance of dye solutions, conducted gravimetric analysis, titrated acetic acid solutions, explored the ideal gas law, and determined the heat of solution of two salts. With the second-semester laboratory kit, students measured colligative properties, monitored chemical and enzyme kinetics, explored and measured equilibria, determined the K_a of a weak acid and K_sp of calcium hydroxide, and measured voltaic and electrolytic cells. To supplement the wet-lab experiments, we also included dry labs on emission lamps and flame tests, spreadsheets, Lewis structures and VSEPR, and the formation of a complex ion.

Both kits included a colorimeter that was custom designed for this purpose. The colorimeter used a LED as the light source, a photoresistor as the detector, a digital multimeter to measure resistance, and a structure built out of LEGO bricks to hold the components and the cuvette. These colorimeters were feasible to deliver at scale: our organic chemistry and introductory biology labs also used the colorimeters, and colorimeters were sent to a total of 240 students and instructors in Fall 2020.

In this presentation, we describe the creation of experiments for our two semesters of remote labs, the details of the colorimeter, the safety and practicality concerns involved with remote labs, and the materials that were sent home to students.

Mark Lingwood

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