Part 1II: Calibration curve for standard iron solutions 1. Complete the following table correlating absorbance to the iron concentration. The addition of excess bipyridine quantitatively converts all Fe2[Fe(bipy)]2(0.4) Prepare a calibration curve for [Fe(bipy)3]2+ by graphing the above data (absorbance versus concentration) using Google Sheets. Your graph should include a title and labelled axes (including units where appropriate). Your graph should also include a best-fit line from software-calculated linear regression analysis. Attach a hardcopy of your graph to this report. NOTE: Instructions for preparing an acceptable graph begin on page 30 of the introductory section of this manual. (1.0) Write the linear equation (of the form y=mx+b ) for the best-fit line from the data plotted in Part III Question 2. Using the slope, determine the molar absorptivity, , for the [Fe(bipy) ]2+ complex ion. (Assume the path length of the cuvet is 1.00cm.) (1.0) Observation Sheet: Spectrophotometric Determination of Iron Part I: Preparation of standard iron solutions Assessment Part II: Determination of max for the [Fe(bipy)3]2+ complex ion Preparation Part III: Calibration curve for standard iron solutions [Fe"] accuracy /4 Report /5 Deductions Total 10 Concentration of stock iron(II) solution: 4.206104 mol/L Measured max for the [Fe(bipy)3]2+ complex ion: 521.4 nm Part IV: Iron content of an unknown well water sample Unknown Well Water Code 223 Part V: Absorbance of Standard Solution #2 at 600nm Absorbance: 0.021