1.8 understand how to classify a substance as an element, compound or mixture

Element: A substance that cannot be broken down into simpler substances by chemical means. An element is composed of atoms that have the same atomic number.

 Compound: A substance formed when two or more chemical elements are chemically bonded together.
Mixture: A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties.

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1.10 describe these experimental techniques for the separation of mixtures: • simple distillation • fractional distillation • filtration • crystallisation • paper chromatography

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SIMPLE DISTILLATION Diagram Showing the Simple Distillation of a Mixture of Salt and Water USE: To Separate a Liquid from a Solution (E.g Water from a Solution of Salt Water) EXPLANATION: Solution is Heated and Water Vapours will Rise and Evaporate Water Vapours will Pass through the Condenser, where it Cools and Condenses, turning into a Liquid that will be Collected in a Beaker After All the Water is Evaporated from the Solution, the Solute will be Left Behind FRACTIONAL DISTILLATION Diagram Showing the Fractional Distillation of a Mixture of Ethanol and Water USE: To Separate Two or More Liquids that are Miscible with One Another (E.g Ethanol and Water from a Mixture of the Two) EXPLANATION: Solution is Heated at Temperature of Substance with the Lowest Boiling Point This Substance will Rise and Evaporate, and Vapours will Pass through a Condenser, where it Cools and Condenses, turning into a Liquid that will be Collected in a Bea...
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1.13 practical: investigate paper chromatography using inks/food colourings

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PAPER CHROMATOGRAPHY Diagram Showing the Paper Chromatography of Ink and Plant Dye USE: To Separate Substances that have Different Solubilities in a Given Solvent (E.g Different Coloured Inks that have been Mixed to Make Black Ink) METHOD: Pencil Line is Drawn on Chromatography Paper and Spots of Ink / Dye is Placed on it Paper is Lowered into a Bucket of Solvent, Allowing the Solvent to Travel Up the Paper, Taking some of the Coloured Substances with it Allow Chromatography to Occur until the Solvent Reaches the Top of the Paper RESUTS: As the Solvent Travels Up the Paper, Different Substances will have Different Solubilities so will Travel at Different Rates, Causing the Substances to Spread Apart This will show the Different Components of the Ink / Dye - http://igcse-chemistry-2017.blogspot.ae/2017/07/113-practical-investigate-paper.html
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