how would you separate dyes in black-black ink using chromatography
Answers
Well, the black ink is actually consist of two dyes. One is blue and second is red. Chromatography is the separation technique which can be use to separate them . This could be possible with the whatman’s filter paper. Just follow the following steps to separate them.
1) First of all take a whatman filter paper’s strip.
2) with the help of pencil draw the line just 3 cm above the lower end of it.Then put your sample( which is ink drop in this case) just at the line's centre. Then give the time for drying.
3) Take a glass jar filled with water and put the filter paper in it such that ink drop on the paper remain above the level of water in the glass Then cover jar with some suitable thing and give the resting time. By the time as the water will rise on the filter paper the black ink components will also separated.
Then just remove your sample and dry it . There will be different spots that can easily be distinguished . One will be for the blue dye and one of them will be for red dye . The remaining spot will illustrate the pure solvent.
A paper chromatography experiment can be performed to separate dyes present in black ink in the following manner:
1. Take a thin, long strip of filter paper and draw a 3 cm long line from one end with a pencil.
2. Put a small drop of black ink at the centre of the pencil line and let it dry.
3. When it is dry, lower the paper strip into a tall glass jar containing some water in its lower part (keep the pencil line at the bottom). The upper end of the paper strip should be attached to a glass rod with cellotape. The lower end of the paper strip should dip in water but the pencil line should stay above the water level in the jar.
4. The water will gradually rise up the filter paper strip by capillary action. As it moves up it will take along the dyes present in the ink. The dye which is more soluble in water will dissolve first, rise faster and produce a coloured spot on the paper at a higher position. The less soluble dyes will dissolve a little later, rise slowly and form coloured spots at lower heights. In this way all the dyes present in the black ink will get separated and form separate coloured spots.
5. Remove the filter paper strip from the jar when the water reaches the top end of the strip and let it dry. The paper with the separate coloured spots is known as a chromatogram.