2 Chromatography Experiment

Question

In a chromatography experiment, a student calculated an Rf value for alanine of 0.70 and 0.91 for leucine. Which amino acid traveled higher on the chromatography paper? Explain your reasoning

 

In a chromatography experiment,  a student calculated that the solvent front was 6.8cm above the starting line. Arginine traveled  a distance of 4.9cm and glycine traveled 3.4cm . What Rf values would the student calculated for arginine and glycine?

 

Please help teacher explained but confused about the whole class with this question.

Answer 1

Since the Rf value is calculated as distance spot moved/distance solvent front moved, the higher the Rf value, the further that spot has moved.  Thus, in your question, leucine traveled higher on the paper. 

 

Arginine Rf = 4.9 cm/6.8 cm = 0.72

Glycine Rf = 3.4 cm/6.8 cm = 0.50