What is the oxidation state of iron in the ferrous phenanthrolin

This week’s exercise focuses on the colorimetric determination of iron concentration in solution. To do thisweek’s pre­lab, please read through the SUSB­015 exercise (p. 47­51) in your lab manual first to familiarizeyourself with the procedure.Reference lecture notes are available on the course website(http://www.ic.sunysb.edu/Class/che134/lectures/pcoliron.pdf) and reference lecture video is available underthe Blackboard “EchoCenter” link.Using a 33 mg L­1 iron stock solution, a series of solutions was made as described on p. 49 in your labmanual. The absorptions of these solutions were measured, and the resulting data are reported below:EntryVol. Fe(phen)3 used / mLAbsorption / au10021.070.07632.020.15544.080.30256.190.40167.280.54579.760.681Plotting these data and fitting them to a linear function yields a line with slope 0.214 with R 2 = 0.993; the plotlooks like this:What is the oxidation state of iron in the ferrous phenanthroline complex?Enter Your Answer:Question 2( 1 point )How many mL of 1.39 x 10­2 M phenanthroline would be required to convert all of the ferrous ion in 100 mLof 6.61E­05 M ferrous sulfate solution to the ferrous phenanthroline complex?Enter Your Answer:Question 3( 0.5 points )In the formation of the complex, hydroquinone acts as a(n):a) bufferb) catalystc) complexing agentd) reducing agente) oxidizing agentf) dyeEnter Your Answer: A B C D E FQuestion 4( 0.5 points )The complex is formed in a solution buffered at a pH that is:a) basicb) neutralc) acidicd) positivee) negativef) imaginaryEnter Your Answer: A B C D E FQuestion 5( 0.5 points )Questions 5­11 ask about the concentrations of ferrous ion in each of the diluted samples enumerated inthe table in Question 1. What is the concentration of the ferrous­phenanthroline complex in the dilutedsolution prepared from 0.00 mL of the iron stock solution (e.g. entry 1)?Enter Your Answer:Question 6( 0.5 points )What is the concentration of the ferrous­phenanthroline complex in the diluted solution prepared from 1.07mL of the iron stock solution (e.g. entry 2)?Enter Your Answer:Question 7( 0.5 points )What is the concentration of the ferrous­phenanthroline complex in the diluted solution prepared from 2.02mL of the iron stock solution (e.g. entry 3)?Enter Your Answer:Question 8( 0.5 points )What is the concentration of the ferrous­phenanthroline complex in the diluted solution prepared from 4.08mL of the iron stock solution (e.g. entry 4)?Enter Your Answer:Question 9( 0.5 points )What is the concentration of the ferrous­phenanthroline complex in the diluted solution prepared from 6.19mL of the iron stock solution (e.g. entry 5)?Enter Your Answer:Question 10( 0.5 points )What is the concentration of the ferrous­phenanthroline complex in the diluted solution prepared from 7.28mL of the iron stock solution (e.g. entry 6)?Enter Your Answer:Question 11( 0.5 points )What is the concentration of the ferrous­phenanthroline complex in the diluted solution prepared from 9.76mL of the iron stock solution (e.g. entry 7)?Enter Your Answer:Question 12( 1 point )What is the Beer’s Law constant for the complex in L mg­1?Enter Your Answer:Question 13( 0.5 points )What is the absorption of a solution whose concentration is 1.14 mg/L?Enter Your Answer:Question 14( 0.5 points )What is the concentration in mg L­1 of a solution whose absorption is 0.574 au?Enter Your Answer:Question 15( 1 point )An unknown solution containing iron at a concentration between 10 and 50 mg/L is analyzed as describedin SUSB­015. 10.0 mL of the unknown solution is diluted to 50.0 mL with the appropriate reagents toconvert the ferrous ion and form the ferrous phenanthroline complex. The diluted solution has an absorptionof 0.514 au. What is the concentration (in mg L­1) of ferrous ion in the diluted solution?Enter Your Answer:Question 16( 1 point )What is the concentration of iron in the unknown solution, in mg L ­1?Enter Your Answer: