A student spots a black ink sample 1.5 cm from the bottom of a strip of chromatography paper and develops it in 70/30 isopropanol/water. The solvent front travels 8.0 cm from the spot. Three components are observed: blue (3.2 cm), red (5.6 cm), yellow (7.2 cm), all measured from the original spot.
What error is introduced if the original ink spot is below the solvent level when the paper is placed in the developing chamber?
- Acheck_circle
The ink dissolves into the solvent reservoir, distorting or eliminating spots on the paper
- B
The yellow component will appear first instead of last
- C
The solvent will not climb the paper
- D
The Rf values become exactly 1.0 for all components
Explanation
Submerging the spot causes the ink to dissolve into the bulk solvent rather than chromatograph up the paper, ruining the separation.