Spectoscopy

SPECTOSCOPYREPORT SHEET | | NAME           RAMY MANNASECTION       052 |
PART I. ABSORRTION SPECTRUM
Concentration of solution used:     0.0232%   Blue 1 Food Dye
Wavelengthnm | Absorbance(no units) | | Wavelengthnm | Absorbance(no units) |
400 | 0.041 | | 590 | 0.141 |
410 | 0.049 | | 600 | 0.189 |
420 | 0.048 | | 610 | 0.181 |
440 | 0.025 | | 620 | 0.299 |
480 | 0.039 | | 630 | 0.323 |
500 | 0.041 | | 640 | 0.231 |
530 | 0.055 | | 650 | 0.189 |
560 | 0.068 | | 660 | 0.061 |
580 | 0.011 | | 690 | 0.004 |

Wavelength chosen for Part II:   630 nm                                  
                       

    PART II.   BEER’S LAW

                  Unknown number   1591

Solution | Concentration | Absorbance |
  1 | 0.0232% | 0.322 |
2 | 0.0186% | 0.278 |
3 | 0.0130% | 0.0190 |
4 | 0.0910% | 0.123 |
| Unknown | 0.312 |
               

Concentration of Unknown:From hand graph             2.89 x 10-4 MFrom computer graph   2.76 X 10-4   M |
Correct Value (filled in by instructor) |

Calculations:
Solution # | mL   of distilled water | mL of stock solution | Concentration | ConcentrationMolarity (M)Moles/Liters |
1 | 0 | Stock solution concentrated | 0.0232% | 2.93 X 10-4 |
2 | 2 mL | 8mL concentrated | 0.0186% | 2.35 X 10-4 |
3 | 3 mL | 7 mL diluted2 | 0.0130% | 1.64 X 10-4 |
4 | 3 mL | 7mL diluted3 | 0.0910% | 1.15 X 10-4 |
Solution #1
Molar mass of C37H34N2O9S3Na2 is 792.85
Percentage concentration = 0.0232%   =  

Solution #2
(Volume   X Concentration) in flask after adding water   =   (Volume   X Concentration ) in flask before adding water      
(10 mL   X   Concentration in flask after adding water)     =   ( 8 mL   X   0.0232% )  

Solution #3
(10 mL   X   Concentration in flask after adding water)     =   ( 7 mL   X   0.0186% )  

Solution #4
(10 mL   X   Concentration in flask after adding water)     =   ( 7 mL   X   0.0130% )  



Post-Lab Questions (answer on back of this sheet...