Post lab for General Chemistry Worksheet

In this section, you will need to submit a typed Word document answering all the post lab questions below. Make sure to include an appropriate title, your name and section number at the top of the page.

1. Explain Beer's Law and identify each component in the equation. What does each component stand for and what is the unit (if any). Relate your linear equation to the Beer's Law (5 points)

2.Explain the purpose of using UV-vis spectroscopy for this particular experiment. What is the maximum wavelength in nm that was used to collect the absorbance value of Fe(SCN)2+ ? (5 points)

3.Use the absorbance and concentration data from the first part of the lab to create the calibration plot of Fe(SCN)2+. The calibration plot will need to have the correct title of the graph, x and y labeling, linear equation, and R-square value displayed. You can plot the graph using Excel then copy the graph into Word. (10 points)

4. Which reactant (Fe3+ or SCN-) is in excess and which is limiting? What is the purpose of making one reactant in excess? (Connect to Le Chatelier's Principle ) How will you know the concentration of Fe(SCN)2+ ? (10 points)

5. Construct your ICE tables using the data and absorbance values collected in the lab to calculate the concentrations at equilibrium. Use the ICE table to calculate Keq. Show your own calculations. (10 points)

Note: For Question 5, calculate the ICE table and Keq for each unknown solution and then average out the Keq at the end. Use Beer's Law with the given absorbance values to calculate the M concentration of Fe (SCN)2+ , then set the ICE table for each test tube solution. Then, use M1V1=M2V2 to calculate the concentrations at equilibrium.