This experiment is used to introduce the Lambert-Beer law and demonstrates the relationships between absorption and concentration. Quantitative analyses by photometry can also be performed for other coloured solutions based on the same principle. Numerous colourless compounds, e.g. phosphate or iron ions, can be determined photometrically after their chemical conversion into coloured complex compounds.
What you can learn about
- Law of Lambert-Beer
- Relation of absorption of light and the concentration of a liquid
- Principles of photometry