The purpose of this lab is to evaluate light absorption in a variety of solutions to identify an unknown solution’s concentration by using a spectrophotometer to measure a particular substances absorption of radiation at a precise wavelength in the visible region of the spectrum to construct a concentration curve. This was then compared to the peak of absorbance of the unknown to determine the concentration of the unknown substance (Kotz, 2014).
Spectroscopy is the study of light, which can be thought of as magnetic and electric waves or as photons, massless particles that travel as energy (Quantitative Spectroscopy: Theory and Practice, Brian C. Smith). To study light we often use a spectrophotometer is the contraption consisting of a white light source through a prism demonstrating refraction, which allows us focus individually on the multiple wavelengths emitted (Brian C. Smith). A= εlc or Beer’s Law states the relationship between the absorbance of a solution and the concentration of the absorbing analyte (Food Analysis, S. Suzanne Nielsen). The variable ε represents the molar absorptivity differs with the wavelength of light used in the measurement. A is the absorbance, c is the concentration and l represents the path length. Beer’s Law strictly applies to certain conditions, such as a homochromatic light source, dilute solutions and lastly a measurement of optimum wavelength also known as the absorbance peak (Haven, 1994). Absorption spectrum is defined as the absorbance of light at different wavelengths on a specific solution (Swamy, 2009). Due to the