A food scientist is investigating the artificial colorings used in a brand of sports drink. She uses paper chromatography with ethyl acetate as the solvent to compare the dye extract from the sports drink with four reference standard food dyes (A, B, C, and D).
What is the stationary phase in this paper chromatography experiment?
Explain how the components of a mixture are separated using paper chromatography.
The diagram below shows the results of her chromatogram. The distance from the pencil baseline to the solvent front is measured to be 12.5 cm12.5\text{ cm}12.5 cm.
Calculate the RfR_fRf value of the red spot (at 7.5 cm7.5\text{ cm}7.5 cm) in standard A. Show your working.
Which reference standard dye (A, B, C, or D) matches the coloring used in the sports drink? Explain how you can tell.