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.