Year 10 Chemistry TRIPLE Learning Cycle 5 Overview How can chemical properties be analysed in industry?

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1 Learning Cycle Overview: Year 10 Chemistry TRIPLE Learning Cycle 5 Overview How can chemical properties be analysed in industry? Line of enquiry 1: Hypothesis 1 Hypothesis 2 Hypothesis 3 Hypothesis 4 Are man-made metals more useful than pure metals? Melted salt conducts electricity. Diamonds conduct electricity. Metals can change shape on their own. Extracting metals is more expensive than recycling them. Week 1 Line of enquiry 2: Hypothesis 5 Hypothesis 6 Hypothesis 7 Hypothesis 8 How has instrumental analysis affected the chemical industry? Instrumental analysis is slow. Reactant masses can be used to find the formula of a compound. Equations can be used to find masses. All reactions produce 100% of the products. Week 2

2 Intentions for learning from AQA: Ionic compounds have regular structures (giant ionic lattices) in which there are strong electrostatic forces in all directions between oppositely charged ions. These compounds have high melting points and high boiling points because of the large amounts of energy needed to break the many strong bonds. When melted or dissolved in water, ionic compounds conduct electricity because the ions are free to move and carry the current. Atoms that share electrons can also form giant structures or macromolecules. Diamond and graphite (forms of carbon) and silicon dioxide (silica) are examples of giant covalent structures (lattices) of atoms. All the atoms in these structures are linked to other atoms by strong covalent bonds and so they have very high melting points. In diamond, each carbon atom forms four covalent bonds with other carbon atoms in a giant covalent structure, so diamond is very hard. In graphite, each carbon atom bonds to three others, forming layers. The layers are free to slide over each other because there are no covalent bonds between the layers and so graphite is soft and slippery. In graphite, one electron from each carbon atom is delocalised. These delocalised electrons allow graphite to conduct heat and electricity. Carbon can also form fullerenes with different numbers of carbon atoms. Fullerenes can be used for drug delivery into the body, in lubricants, as catalysts, and in nanotubes for reinforcing materials, eg in tennis rackets. Line of enquiry one: Are man-made metals more useful than pure metals? The elements in the central block of the periodic table are known as transition metals. Like other metals they are good conductors of heat and electricity and can be bent or hammered into shape. They are useful as structural materials and for making things that must allow heat or electricity to pass through them easily. Copper has properties that make it useful for electrical wiring and plumbing. Low density and resistance to corrosion make aluminium and titanium useful metals. Metals conduct heat and electricity because of the delocalised electrons in their structures. The layers of atoms in metals are able to slide over each other and so metals can be bent and shaped. Alloys are usually made from two or more different metals. The different sized atoms of the metals distort the layers in the structure, making it more difficult for them to slide over each other and so make alloys harder than pure metals. Shape memory alloys can return to their original shape after being deformed, eg Nitinol used in dental braces. Iron from the blast furnace contains about 96% iron. The impurities make it brittle and so it has limited uses. Most iron is converted into steels. Steels are alloys since they are mixtures of iron with carbon. Some steels contain other metals. Alloys can be designed to have properties for specific uses. Low-carbon steels are easily shaped, high-carbon steels are hard, and stainless steels are resistant to corrosion. Most metals in everyday use are alloys. Pure copper, gold, iron and aluminium are too soft for many uses and so are mixed with small amounts of similar metals to make them harder for everyday use. Ores contain enough metal to make it economical to extract the metal. The economics of extraction may change over time. Ores are mined and may be concentrated before the metal is extracted and purified. Unreactive metals such as gold are found in the Earth as the metal itself but most metals are found as compounds that require chemical reactions to extract the metal. Metals that are less reactive than carbon can be extracted from their oxides by reduction with carbon, for example iron oxide is reduced in the blast furnace to make iron. Metals that are more reactive than carbon, such as aluminium, are extracted by electrolysis of molten compounds. The use of large amounts of energy in the extraction of these metals makes them expensive. Copper can be extracted from copper-rich ores by heating the ores in a furnace (smelting). The copper can be purified by electrolysis. The supply of copper-rich ores is limited. New ways of extracting copper from low-grade ores are being researched to limit the environmental impact of traditional mining. Copper can be extracted by phytomining, or by bioleaching. Copper can be obtained from solutions of copper salts by electrolysis or by displacement using scrap iron. Aluminium and titanium cannot be extracted from their oxides by reduction with carbon. Current methods of extraction are expensive because: there are many stages in the processes large amounts of energy are needed. j) We should recycle metals because extracting them uses limited resources and is expensive in terms of energy and effects on the environment.

3 Lesson 1: Melted salts conducts electricity. Key words: lattice, electrostatic forces. Ionic compounds have regular structures (giant ionic lattices) in which there are strong electrostatic forces in all directions between oppositely charged ions. These compounds have high melting points and high boiling points because of the large amounts of energy needed to break the many strong bonds. When melted or dissolved in water, ionic compounds conduct electricity because the ions are free to move and carry the current. State the properties of ionic compounds Describe and illustrate the structure of ionic compounds Explain why ionic compounds conduct electricity. Evaluate the hypothesis Peer assessment of exam questions on ionic structures and properties. Lesson 2: Diamond conducts electricity. Key words: allotrope, van der Waals, fullerenes. Atoms that share electrons can also form giant structures or macromolecules. Diamond and graphite (forms of carbon) and silicon dioxide (silica) are examples of giant covalent structures (lattices) of atoms. All the atoms in these structures are linked to other atoms by strong covalent bonds and so they have very high melting points. In diamond, each carbon atom forms four covalent bonds with other carbon atoms in a giant covalent structure, so diamond is very hard. In graphite, each carbon atom bonds to three others, forming layers. The layers are free to slide over each other because there are no covalent bonds between the layers and so graphite is soft and slippery. In graphite, one electron from each carbon atom is delocalised. These delocalised electrons allow graphite to conduct heat and electricity. Carbon can also form fullerenes with different numbers of carbon atoms. Fullerenes can be used for drug delivery into the body, in lubricants, as catalysts, and in nanotubes for reinforcing materials, eg in tennis rackets. Recall the term allotrope. Illustrate and describe the bonding in diamond and graphite. Describe the properties of the allotropes of carbon. Explain why graphite conducts electricity and diamond does not. Evaluate the hypothesis Self-assessment of exam questions on covalent structures.

4 Lesson 3: Metals can change shape on their own. Key words: alloys. Metals have many useful properties which make them useful as structural materials, for making things which conduct heat and electricity and plumbing. Alloys contain a mixture of metal which make them harder than pure metals. Most everyday metals are alloys. Shape memory alloys can return to their original shape after being deformed. Steel is an alloy of iron and carbon which can have specific properties for its use. Recall properties of metals. Explain why metals conduct electricity. Explain why alloys are harder than pure metals. Evaluate the importance of using alloys in different industries. Evaluate the hypothesis Teacher assessed metal questions. Planned reach activity. Lesson 4: Extracting metals is more expensive than recycling them. Key words: Reduction, electrolysis, recycling, smelting, Metals which are more reactive than carbon are extracted by electrolysis of molten compounds, which is very expensive. Metals which are less reactive than carbon are extracted by reduction with carbon. Extracting metals is more expensive in terms of energy and effects on the environment in comparison to recycling. Copper can be extracted by phytomining, or by bioleaching as well as smelting. Describe the process of electrolysis and reduction. Explain the limitations with extracting aluminium, titanium and copper. Evaluate why extracting metals is more expensive than recycling. Evaluate the various methods of extracting copper from its ore. Evaluate the hypothesis Act on teacher feedback. Self-assessment of exam question.

5 Line of enquiry two: How has instrumental analysis affected the chemical industry? Intentions for learning from AQA GCSE specification: Elements and compounds can be detected and identified using instrumental methods. Instrumental methods are accurate, sensitive and rapid and are particularly useful when the amount of a sample is very small. Chemical analysis can be used to identify additives in foods. Artificial colours can be detected and identified by paper chromatography. Gas chromatography linked to mass spectroscopy (GC-MS) is an example of an instrumental method: gas chromatography allows the separation of a mixture of compounds the time taken for a substance to travel through the column can be used to help identify the substance the output from the gas chromatography column can be linked to a mass spectrometer, which can be used to identify the substances leaving the end of the column the mass spectrometer can also give the relative molecular mass of each of the substances separated in the column. The percentage of an element in a compound can be calculated from the relative mass of the element in the formula and the relative formula mass of the compound. The empirical formula of a compound can be calculated from the masses or percentages of the elements in a compound. The masses of reactants and products can be calculated from balanced symbol equations. Even though no atoms are gained or lost in a chemical reaction, it is not always possible to obtain the calculated amount of a product because: the reaction may not go to completion because it is reversible some of the product may be lost when it is separated from the reaction mixture some of the reactants may react in ways different from the expected reaction. The amount of a product obtained is known as the yield. When compared with the maximum theoretical amount as a percentage, it is called the percentage yield. In some chemical reactions, the products of the reaction can react to produce the original reactants. Such reactions are called reversible reactions and are represented: A + B C + D For example: ammonium chloride ammonia + hydrogen chloride Lesson 5: Instrumental analysis is slow. Lesson 6: Reactant masses can be used to find the formula of a compound. Key words: gas-chromatography, mass spectrometry, chromatography. Elements and compounds can be detected and identified using instrumental methods. Instrumental methods are accurate, sensitive and rapid and are particularly useful when the amount of a sample is very small. Chemical analysis can be used to identify additives in foods. Artificial colours can be detected and identified by paper chromatography. Gas chromatography linked to mass spectroscopy (GC-MS) is an example of an instrumental method. Describe how artificial colours are identified. Explain how GC-MS works. Create instructions for GC-MS operation. Evaluate the hypothesis Key words: relative mass, empirical formula, percentage mass Mastery teaching The percentage of an element in a compound can be calculated from the relative mass of the element in the formula and the relative formula mass of the compound. The empirical formula of a compound can be calculated from the masses or percentages of the elements in a compound. Recall the terms relative atomic mass and relative formula mass. Calculate relative formula masses. Calculate empirical formulas of various compounds. Evaluate the hypothesis Numeracy focus lesson Peer assessed instructions for GC-MS using mark schemes. Numeracy focus lesson Teacher assessed calculations.

6 Lesson 8: All reactions produce 100% of the product. Key words: actual yield, theoretical yield, reversible reaction. Mastery teaching The amount of a product obtained is known as the yield. When compared with the maximum theoretical amount as a percentage, it is called the percentage yield. Even though no atoms are gained or lost in a chemical reaction, it is not always possible to obtain the calculated amount of a product because: the reaction may not go to completion because it is reversible some of the product may be lost when it is separated from the reaction mixture some of the reactants may react in ways different from the expected reaction. In some chemical reactions, the products of the reaction can react to produce the original reactants. Such reactions are called reversible reactions and are represented: A + B C + D For example: ammonium chloride ammonia + hydrogen chloride. Calculate percentage yields of reactions. Identify possible reasons for not obtaining 100% yield. Explain why some reactions are reversible. Evaluate the hypothesis Numeracy focus lesson Self-assessed symbol equations and calculations. REACH activities planned for pupils to take autonomy over their work. Work through progressively harder calculations. Act on feedback.

7 Lesson Practical Opportunity 1 Conductivity of ionic compounds 2 Conductivity of graphite 3 Shape change alloys Practical Opportunities Demonstration/Experiment Details Run through needed/ra completed? Demo Demo Demo Show how ionic compounds can conduct electricity when dissolved. Show the conductivity of graphite and look at why. Show how some alloys will change shape depending on temperature. 4 Electrolysis Experiment Separate copper sulphate in solution using electrolysis. 5 Chromatography Experiment Separate the dyes that ink are made up of using chromatography. 6 N/A 7 N/A needed, useful precautions with water and electricity. needed, useful precautions with electricity. needed just throw the alloy into hot water to get it to return to its set shape. needed, useful precautions with water and electricity. needed. Materials Provided Salt Water Electric kit (battery, bulb, wire, multimeter) 100cm3 beaker Stirrer Carbon rods (Graphite) Electric kit (battery, bulb, wire, multimeter) Molymods kits (to make graphite and diamond) Hot water Kettle Shape change alloy already set into a shape Water Trough Per group: Copper sulphate or copper chloride solution 100cm3 beakers Carbon rods Electric kit (battery, wires) Water 100cm3 beakers Chromatography paper Pens with water soluble inks Link for Practical

8 Home learning Balancing equation and mass from equations HL