Question

In one experiment the solvent moved 3.0 inches while one of the components moved 5.2 cm. Calculate the Rf value for this component

Answer 1

Retention Value (or Rf value) is defined as the ratio of the distance moved by the component and the distance moved by the the solvent (also known as the Solvent front). Both the distances are measured from the common Origin or Baseline (the point where the sample is initially spotted on TLC).

Rf = (Distance from Baseline travelled by the compnent) / (Distance from Base line travelled by Solvent).

Distance from Baseline travelled by the component = 5.2 cm

Distance from Baseline travelled by Solvent = 3.0 inches

= 3.0 x 2.54 cm (1 inch = 2.54 cm)

= 7.62 cm

So, Rf of the component = 5.2 cm / 7.62 cm = 0.68