A child wanted to separate the mixture of dyes constituting a sample of ink. He marked a line by the ink on the filter paper and placed the filter paper in a glass containing water as shown in figure. The filter paper was removed when the water moved near the top of the filter paper.
- What would you expect to see, if the ink contains three different coloured components?
- Name the technique used by the child.
- Suggest one more application of this technique.
Answer:
- The colour component which is more soluble in water dissolves first, rises faster and produces a colour band (spot) on the paper at a higher position. The less soluble colour components dissolve a little later, rise slower and form coloured bands at lower heights. In this way, three different bands will be observed.
- Chromatography
- To separate the pigments present in chlorophyll.