Answer:You will use Beer's law. A = εmCl Explanation: The basic idea here is to use a graph plotting Absorbance vs. Concentration of known solutions. Once you have that you can compare the absorbance value of an unknown sample to figure out its concentration. http://intro.chem.okstate.edu/ChemSource/Instrument/inst4.htm You will be applying Beer's law to calculate the concentration. The equation for Beer's law is: A = εmCl (A=absorbance, εm = molar extinction coefficient, C = concentration, l=path length of 1 cm) You should have a data set which was used to create a standard curve. The graph should plot concentration (independent variable) on the x-axis and absorption (dependent variable) on the y axis. You'll need to add a line of best fit to the data points and determine the equation for the line. The equation should be in y=mx + b form. y = absorbance (A) Note: no unit for absorbance x = concentration (C) Note: unit is M or mol/L m = (εm) = slope or the molar extinction coefficient in beers law which has units of M−1cm−1 So A = εmC +b If you solve for C you should get C = (A-b)/εm So if you substract your y-intercept from the absorbance and divide by the slope, you are finding the concentration of your sample. Here is video of a lab applying this concept.
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Noel PaullerThank for visiting my blog where I post thoughts from the random corner of the universe which is my brain. Archives
October 2022
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