1. A calibration curve constructed from absorbance values of solutions containing a known concentration of permanganate ions has the following best-fit line:  y = (3.62 × 103 L/mol) x where y is the absorbance of the solution at 525 nm and x is the concentration of MnO4- (aq) in mol/L.  The pathlength of the cuvettes used in the experiment is 1 cm.  Based on this information, what is the molar absorptivity of MnO4- (aq) at 525 nm?  Be sure to include units in your answer. 

Molar absorptivity of MnO4- (aq) at 525 nm: __________________________  

2. A sample of steel weighing 0.1863 g was dissolved and the manganese present was converted to MnO4- (aq).  Water was then added to give a final solution volume of 100.00 mL.  A sample of this solution was examined and was found to have an absorbance at 525 nm of 0.620 (pathlength = 1 cm).  What is the percent Mn in this sample of steel?