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.