Tool 1: Experimental Techniques (HL IB Biology)

Some students used paper chromatography to separate out the photosynthetic pigments in a leaf. The resulting chromatogram can be seen below.

Using the measurements made by the students, calculate the R_f values for carotene and chlorophyll B and complete the table below.

Explain what the results in part (a) show about the properties of the photosynthetic pigments.

The method used to prepare the photosynthetic pigments for chromatography requires the use of propanone. As a health and safety precaution, a student using this method decided to use water instead of propanone.

State what the student’s results would have shown and explain why..