Calorimetry Lab Report

I. Objective: The objective of this experiment is to determine the mass percent of iron in an iron compound using a spectrophotometer. From there, determine which iron compounds are in the stock room bottles based off of the experimental mass percent results.
II. Introduction: The objective is to determine the mass percent of iron in an iron compound using a spectrophotometer. From there, determine which iron compounds are in the stock room bottles based off of the experimental mass percent results. The objective is going to be met by first using absorption spectroscopy. This will be done by making 6 dilutions of a known compound of FeNH4(SO4)2 . Absorption spectroscopy involves placing the 6 diluted solutions into the spectrophotometer. This will measure the light absorption of the individual dilutions. The absorption values will be the y values on the Beers Law Plot. Beers Law shows that there is a relationship between absorption and concentration so the x value on the Beers Law Plot will be the concentration of the 6 diluted iron solutions. To calculate the concentration, the equation is M1V1=M2V2 solving for the final molarity. Then the
Conclusion: Unknown solution A was Fe2(SO4)3 * 5H2O. Unknown solution B was Fe(NH4)(SO4)2 * 12H2O. Unknown solution C was FeCl3 * 6H2O. Unknown solution D was Fe(NO3)3 * 9H2O. The professor should have confidence that these are the correct identifications for the bottles because although the groups as a whole did not have the best precision and accuracy, it was mainly due to one or two groups having poor results. On a group to group basis though, there was very good accuracy. The results of each compound clearly identified the unknown with one of the iron compounds. There was no guessing which unknown was which compound because each experimental mass percent matched up well with the theoretical mass percent of the iron compounds. So a lot of confidence is behind the accuracy of the identification of the unknown