Spectrophotometry is a quantitative analysis that is essential the subject of chemistry. It measures reflection and transmission of various materials as a function of wavelength. This is a relatively basic concept that is often taught in early chemistry courses such as high school chemistries or general chemistry classes. Spectrophotometry uses a number of instruments that each measures a different range of wavelengths. The instrument that our group created was a colorimeter, which can measure wavelengths in the visible light range. This range is approximately 400-700nm. Three experiments were designed to incorporate this instrument; that are relatively low in costs and great for a high school/general level chemistry students. These experiments do not require a great deal of materials and are not for highly skilled chemists.
The basic principles of the physics of color are often taught in high school chemistry and physics classes around the country. Unfortunately, many of these spectrophotometric experiments use harmful solvents to dissolve very small quantities of solute in order to produce a solution with the proper concentration to be analyzed by a colorimeter. Most high schools do not have the ability to dispose of organic waste, and creating a solution of a specific concentration for high school students would likely distract them from the intended task. The proposed colorimetry experiment requires only colored crêpe paper and distilled water in order to prepare solution to analyze. The paper is very inexpensive and the water-soluble dye is non-toxic and can therefore be easily disposed of. Three basic experiments can be run with these materials and the colorimeter we built in lab: the exploration of spectral characteristics of different color solutions, create a calibration curve and explore Beer’s law, and finally explore simultaneous