Iron In Drinking Water Essays - Spectroscopy, Absorbance

Iron In Drinking Water Purpose: The purpose of this lab was to gain the quantitative measure of the color difference between Transmitance and absorbance in 8 different samples of water containing varying amounts of iron in a range between 5-100ppm, so that we know which samples where exceptable for drinking. Data: The Mystery Solution had a transmittance of 62.2% Calculations: 80ppm(25ml)= 20ml 100ppm This means that in order to get 25ml of 80ppm solution 20ml of water must be added to the previous solution. Absorbtion: y=2-Log (concentration) Y=2-Log (10.3) Y=0.98 Mystery Solution: Absorbance= .0103 X concentration of mystery solution Absorbance= .05011 Mystery Solution: .206209615=.0103* concentration of mystery solution Concentration=20 Question 2. 125/20=6.25 x Less Question 3. 8 ounces (1 quart/32 ounces) (1 liter/1.057 quarts)=.2365 Discussion: The Spectrophotometer measures the absorbance of light, a beam of light is passed through a transparent tube containing the absorbing liquid. The intensity of light reaching a detector is compared to the intensity reaching the detector in the absence of the absorbing material. Beer's law is that the absorbance (defined as log) is proportional to the concentration.