Question

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

Answer 1

Answer: 0.72 AND 0.5 RESPECTIVELY/.

Explanation:

The Rf value is defined as the ratio of the distance moved by the solute (i.e. the dye or pigment under observation) and the distance moved by the the solvent ie the migration of the solvent along the paper, where both distances are measured from point where the sample is first spotted on the paper.

Rf  value= (migration distance of substance)/(migration distance of solvent front)

or

Rf  value=Distance from Baseline travelled by Solute /Distance from Baseline travelled by Solvent (Solvent Front)

For Arginine Rf = (4.9 cm)/(6.8 cm) = 0.72

For glycine Rf = (3.4 cm)/(6.8 cm) = 0.5