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Similar to chemistry gcse Particles and Purification.pptx
chemistry gcse Particles and Purification.pptx
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- 2. 1.PARTICLES AND PURIFICATION PART 1 1.1SOLIDS, LIQUID, GASES 1.2 DIFFUSION 1.3 APPARATUS FOR MEASURING PART 2 1.4 PAPER CHROMATOGRAPHY 1.5 PURITY OF SUBSTANCE 1.6 METHOD OF PURIFICATION
- 3. Paper chromatography the methodof separating pigments(coloured substances) using filter paper
- 4. FACTORS DETERMINING HOWFAST THE PIGMENTS MOVE ACROSS THE FILTER PAPER The pigment have different solubilities in the solvent The pigment have different degrees of attraction for the the filter paprer The type of solvent also effect how far the pigment will travel across the paper USES OF CHROMATOGRAPHY: 1.identifing the substances in the mixture 2.Seperation and purification of the substance in the mixture
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- 7. PURE SUBSTANCES • APURE SUBSTANCE CONSISTS ONLY OF ONE ELEMENT OR ONE COMPOUND • A MIXTURE CONSISTS OF TWO OR MORE DIFFERENT SUBSTANCES, NOT CHEMICALLY JOINED TOGETHER • DIFFERENT TYPES OF CHEMICAL SUBSTANCE • AN ELEMENT CONTAINS JUST ONE TYPE OF ATOM • A COMPOUND CONTAINS TWO OR MORE TYPES OF ATOM JOINED TOGETHER • A MIXTURE CONTAINS TWO OR MORE DIFFERENT SUBSTANCES THAT ARE NOT JOINED TOGETHER • THE DIFFERENT SUBSTANCES IN A MIXTURE CAN BE ELEMENTS OR COMPOUNDS
- 8. THE DIFFERENCE BETWEENCOMPOUND AND MIXTURE COMPOUND • COMPOUND HAVE A FIXED COMPOSITION(THE RATIO OF ELEMENTS PRESENT IS ALWAYS THE SAME IN ANY PARTICULAR COMPOUND). • CHEMICAL REACTION MUST BE USED TO SEPARATE THE ELEMENTS IN A COMPOUND. • THERE ARE CHEMICAL BOUNDS BETWEEN ATOMS OF THE DIFFERENT ELEMENTS IN THE COMPOUND. MIXTURE • MIXTURES HAVE NO FIXED COMPOSITION(THE PROPORTIONS VARY DEPENDING ON THE AMOUNT OF EACH SUBSTANCE MIXED TOGETHER) • THE DIFFERENT ELEMENT OR COMPOUNDS IN A MIXTURE CAN BE SEPARATED AGAIN MORE EASILY ( BY PHYSICAL MEANS USING THE DIFFERENCES IN PROPERTIES OF EACH SUBSTANCE IN A MIXTURE) • THERE ARE NO CHEMICAL BONDS BETWEEN ATOMS OF DIFFERENT SUBSTANCES IN A MIXTURE.
- 9. PURITY OF SUBSTANCE •WHY PURITY IS IMPORTANT • PURE ORANGE JUICE • DISTILLED WATER • MEDICINAL DRUGS • PURE SILICON • HOW DO WE KNOW IF THE SUBSTANCE IS PURE • CHROMATOGRAPHY • MELTING AND BOILING POINT • EFFECT OF IMPURITIES ON MELTING AND BOILING POINT • THE MP AND BP ARE NOT SHARP IN IMPURE SUBSTANCE • THE BP INCREASED BY IMPURITIES • THE MP DECREASES BY IMPURITIES
- 10. Distinguishing between puresubstances and mixtures Pure substances have a sharp melting point but mixtures melt over a range of temperatures. This difference is most easily seen when the temperature of a hot liquid is measured as it cools and freezes. The graph shows the cooling curve for a sample of a compound called salol. A cooling curve for salol The temperature stays the same while a pure substance changes state The horizontal part of the graph shows that the salol has a sharp melting point, so it is pure. Impure salol (a mixture of salol and other substances) would produce a gradual decrease over a range of temperatures as it freezes. Graph of the freezing and melting range of a sunstance, between 40 c and 50 c. The temperature changes slightly as an impure substance changes state
- 11. HOW DO WEPURIFY MIXTURES • SOLIDS FROM LIQUIDS • FILTRATION • DECANTING • CENTRIFUGATION • WASHED AND REMOVED • DISSOLVED SOLIDS FROM LIQUIDS • EVAPORATION • LIQUIDS FROM LIQUIDS • FRACTIONAL DISTILLATION
- 12. SEPARATING A SOLIDFROM A SOLUTION FILTRATION DECANTING CENTRIFUGE CRYSTALLIZATION
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- 14. PURIFICATION SIMPLE DISTILLATION ANDFRACTIONAL DISTILLATION
- 15. PURIFICATION PURIFY THE MIXTUREOF SALT AND SAND • ADD WATER TO DISSOLVE THE SALT • SEPARATE SANT AND SALT BY FILLTRATION • USE THE PROCESS OF CRYSTALLIZATION TO FORM SALT CRYSTALS • RISN THE SAND WITH DISTILLED WATER • DRY THE SAND AND SALT CRYSTALS SEPERATELY ON FILTER
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