How does dilution affect absorbance?
As a solution is diluted, the absorbance of the solution is decreased.
The concept of dilution relates molar concentration and volume.
If a 1.0 liter of a 1.0 molar solution is diluted to 2.0 molar solution, the new molar concentration is 0.50. The new concentration has been reduced by one half as the volume was doubled.
Beer's law relates the concept of concentration and absorbance. According to this law, absorbance and concentration are directly proportional. If you increase the original concentration, the absorbance increases and if you dilute the solution(which means you decrease the original concentration), the absorbance will decrease in direct proportion.