Analysis of Colas Brandi Ingram Chemistry 1011 Laboratory, Section 008-129A Instructor: Paul Haupt-Renaud November 15, 2014 My signature indicates that this document represents my own work. Excluding shared data, the information, thoughts and ideas are my own, except as indicated in the references. Discussion and Explanation: How the Spec 20 works: The first goal of this lab was to develop a complete understanding of the Spectronic 20, in terms of how it works, and all of its components. The Spec 20, which is actually a spectrophotometer, is a piece of equipment that is useful when trying to determine different concentrations, absorbance, or percent transmittance. The diagram above is a rough outline of how the spec 20 …show more content…
This means that our data does agree with the theory expected because it reflects light at the appropriate wavelength for green light. The analytical wavelength for the color green would also be 650 because that is where the most light was absorbed. This graph above depicts the same information, in a different way because we were comparing percent transmittance vs. wavelength. Meaning we would actually be looking at the wavelength where the most light was transmitted depict the color of the substance. This is true for the color solutions for red and yellow. However they reflect different wavelengths of light than that of the green solution, which is actually what allows us to perceive these colors as yellow and red, which is shown in the following four …show more content…
Absorbance and concentration are directly proportional and this is all possible because of Beer’s law which states that A(absorbance)=e(molar absorptivity)*l(distance traveled)*(concentration)5. Therefore if given the absorbance you can once again predict concentration because of this relationship, and this agrees with the expected theory because as you have an increase in absorbance you should expect a proportional increase in concentration and this is consistent with our correlation coefficient for the data and line of best fit, which is 0.996. PO43- ion Calibration Curve from K2HPO4 Solution We first began with the same procedure as used for the KmNO4 solution by finding the analytical wavelength, which is expressed in this graph at the maximum