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When you are using coloured pencils or paints which colours do you use to make Green or Purple ?. Separating Dyes in Ink. Learning Objectives : To know that a mixture of two or more solutes which are soluble in a particular solvent can be separated by chromatography
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When you are using coloured pencils or paints which colours do you use to make Green or Purple?
Separating Dyes in Ink Learning Objectives: • To know that a mixture of two or more solutes which are soluble in a particular solvent can be separated by chromatography • To explain how chromatography separates solutes • To be able to conduct an experiment to separate dyes used in colour inks by chromatography • To use chromatography to identify materials
What is chromatography? Method A Method B pipette solvent spot of mixture spot of mixture solvent Chromatography is used to separate mixtures of coloured or non-coloured substances that are soluble in the same solvent. A spot of the mixture is placed on some filter paper. In method A, the solvent is soaked up the paper. In method B, the solvent or is slowly dripped onto the paper. The substances in the mixture get separated because more soluble substances spread along the paper faster.
Practical Activity • Safety First: • Wear safety goggles • Stand up • Tuck your chair & bags under your desk • Tie back long hair
Identifying dyes in a mixture 1 2 3 4 5 6 1 2 3 4 5 6 mixture mixture Chromatography can be used to find out if a dye is made up of a single coloured substance or a mixture. The mixture consists of dyes 3 and 5. Dots of known single dyes are placed alongside the dot for the unknown mixture. After the solvent washes through the paper, the pattern of the dyes in the mixture is compared with the single dyes. Which dyes does the mixture consist of?
Identifying dyes in a mixture Which dyes are in the mixture? • 2 3 4 5 6 • 2 3 4 5 6 mixture mixture The mixture consists of dyes 1 and 4.
Chromatography R G B X 1 2 3 Z Chromatography can be used to separate a mixture of different inks. Some example questions… 1) Ink X contains two different colours. What are they? 2) Which ink is ink Z made out of?
Separating Dyes in Ink Learning Objectives: • To know that a mixture of two or more solutes which are soluble in a particular solvent can be separated by chromatography • To explain how chromatography separates solutes • To be able to conduct an experiment to separate dyes used in colour inks by chromatography • To use chromatography to identify materials