The accompanying narrative on Spectrophotometer may also vie

The accompanying narrative on \"Spectrophotometer\"; may also view videos: Video (length 6:26) on use of spectrophotometer https://www.youtube.com/watch?v=xHQM4BbR040 How to Use EXCEL to Make a Standard Curve https://www.youtube.com/watch?v=R6WiXa8R73c Absorbance Spectrum for CoCl_2 (50 mg/mL) Plot this data on graph paper to make your absorption spectrum for cobalt chloride; your figure needs a descriptive title and all axes must be labelled. Why is it important to clean the outside of the sample tubes? What wavelength is the peak absorbance ofCoCl_2? Would you expect an absorption spectrum curve of the same shape as that for cobalt chloride for a different molecule like chlorophyll? Why?

Solution

1) If the cuvettes are not clean and dry you are supposed to rinse the cuvettes until they are clean and then air dry them until there is no water droplet or water mark left behind, it is important to clean the inner, outer and bottom part of the cuvette because fingerprints, liquid droplets and smudges on the cuvette gives false absorbance reading as even a small disturbance in light rays can give a varying result.

2) 425nm

3) Yes, you can get an absorption spectrum of chlorophyll as that of any other compound. Chlorophyll also absorbs light at a certain wavelength and hence it can also be drawn in the form of a spectrum.