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.