Jonathan Chen/4th pd.
Beer’s Law Pre-Lab
a. The term “absorbance” as used in this lab means the amount of light absorbed by a sample
b. The percent of light that passes through a solution without any absorbance
c. Mathematically, a logarithmic relationship exists between absorbance and percent transmittance
1)
2) As the concentrations of the colored solution increases, the absorbance readings should increase
because the number of moleecules to interact with the light increases. If your absorbance readings
remain constant throughout the experiment, you
3) The term “standard solution” means a 1M solution at 25◦C and at 1atm
4) Beer-Lambert Law
5)
6)
7) It is preferred to express the Beer-Lambert law using absorbance rather than % transmittance
because absorbance is directly proportional to the other parameters, as long as the law is obeyed. Also,
the linear relationship between concentration and absorbance is both simple and straightforward.
8) Molar absorptivity