1. Relating [solute] to Absorbance of Light Use of the Spectronic 20—a Visible Spectrophotometer

2. What’s this all about? As you will see, the amount of light absorbed by a coloured solution can be related to [solute]. We use a spectrophotometer to measure the amount of light that is absorbed by a solution. The opposite of absorbance of light is transmittance of light.

5. That is, if a solution transmits a lot of light, it therefore absorbs little light. Absorbance and transmittance are opposites—sort of. More on this later.

6. Electromagnetic Spectrum long λshort λ radio/TV microwaves IR v I s I b l e UV X-rays gamma rays low Ehigh E

7. The Visible Spectrum λ=700 nm λ=400 nm