# Lab II.docx - SPECTROPHOTOMETRIC DETERMINATION OF MANGANESE...

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SPECTROPHOTOMETRIC DETERMINATION OF MANGANESE Spectrophotometric Determination of Manganese Natalia M. Velázquez López 16 July 2019 IntroductionAll types of radiant energy travel at a speed of 3.00 x 108 m/s through a vacuum. As the labmanual states it, this value is defined as the ‘speed of light.’ Through this experiment, we will seethe two important aspects of the wavelike characteristics in radiant energy- wavelength andfrequency. Furthermore, we will also learn about the electromagnetic spectrum. However, thisexperiment mainly focuses on a very small portion of the spectrum, namely, the ultraviolet. When asubstance absorbs radiant energy, certain electrons absorb that energy ad are raised from a lowenergy state to a higher energy state. Our main concern in this experiment is to see how theabsorbance is directly proportional to the concentration of a solution, also known as the Beer’sLaw, through the relationship between the absorption of radiant energy by a solution and itsconcentration.: 2 Mn2+(aq) + 5 IO4-(aq) + 3 H2O (l) 2 MnO4-(aq) + 5 IO3-(aq) + 6 H+(aq)We will be able to prove this law if the Absorbance vs. Concentration is plotted andgraphed and it results in a straight line. The regression line’s equation is used to determine theconcentration of an unknown solution once the percent of T has been measured. The equation ofBeer’s Law, A=abc, is an efficient way of putting the relationship between absorbance, the pathlength of the solution, and the concentration of the solution, into a numeric form. This displaysthe ideal condition in which these components are proportional to the absorbance.
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