93%(56)52 out of 56 people found this document helpful
This preview shows page 1 - 2 out of 3 pages.
Maura EstesCHE 135, Section 70116 October 2012Lab 6: Spectrophotometric Determination of Mn in SteelPurposeThe overall goal of this experiment was to determine the percent mass of manganese in a steel sample with an unknown amount of manganese using spectrophotometry. Mass, by difference, was calculated for the standard and unknown steel samples. Absorbance was recorded for the permanganate solutions at different dilution levels. Absorbance was also recorded for the unknown solution. Using the mass of the standard steel sample, the concentration of permanganate could be calculated. Using this concentration, the concentration of the permanganate could be calculated for the different dilutions. The absorbance values at the different dilution levels were plotted. Using the best-fit line for the equation from the generated plot and the recorded absorbance of the unknown solution, the concentration of the unknown was calculated and then used, along with the calculated mass of the unknown steel sample to determine the percent of manganese in the unknown steel sample. ProcedureCHE135, General and Analytical Chemistry III Laboratory Manual, Fall Quarter 2012, DePaul University, Department of Chemistry, Experiment 6 (?ou=178414&tId=1120991)Data and ResultsTable 1: Mass by DifferenceInitial Mass (g)Final Mass (g)Mass of Sample (g)Standard Sample73.113172.61550.4976Unknown Sample40.675640.16990.5057This table shows the mass, calculated by difference, of the standard and unknown samples of steel.