9.6. Extraction of metals
A subsection of Chemistry, 0620, through 9. Metals
Listing 10 of 311 questions
Iron is manufactured in a blast furnace. Three of the starting materials added to the blast furnace are coke, iron ore and limestone. Name the other starting material added to the blast furnace. The source of iron in the blast furnace is Fe2O3. Fe2O3 is found in iron ore. Name the main ore of iron which contains Fe2O3. The iron in Fe2O3 is reduced by reaction with carbonmonoxide. The unbalanced symbol equation is shown. Complete the equation. Fe2O3 + CO → CO2 + Fe State the change in oxidation number of iron in the reaction in . from to ������������������������������������������������������������ Explain how the change of oxidation number shows that iron has been reduced. The major impurity in iron ore is silicon(oxide. Limestone is added to the blast furnace to remove this impurity. Write two symbol equations to show how silicon(oxide is removed. For each equation, state the type of chemical reaction that takes place. equation 1 type of chemical reaction equation 2 type of chemical reaction  Iron is converted to steel by mixing it with carbon and other elements. State the term given to a substance which is a mixture of a metal and other elements. Name one element, other than carbon, mixed with iron in the making of stainless steel. Preventing the rusting of steel is important. State the chemical name of rust. Steel can be coated with zinc to prevent rusting. This provides both a barrier method and sacrificial protection. State the term used for coating steel with zinc. Describe another barrier method for preventing rusting. Explain how zinc provides sacrificial protection. 
0620_w23_qp_42
THEORY
2023
Paper 4, Variant 2
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This question is about iron. Describe the bonding in a metallic element such as iron. You may include a labelled diagram as part of your answer. Explain why iron conducts electricity when it is solid. Iron is extracted from hematite in the blast furnace as shown in Fig.5.1. waste gases coke, hematite, limestone molten iron slag air air Give two reasons why coke is added to the blast furnace.  Explain how limestone removes the impurities in the hematite. Hematite contains iron(oxide. Write a symbol equation for the conversion of iron(oxide to iron in the blast furnace. Suggest why the iron produced in the blast furnace is molten. Most iron is converted into steel. Steel is an alloy. Steel is more useful than pure iron because it is harder and stronger. Explain why the structure of alloys causes them to be harder and stronger than pure metals. You may include a diagram as part of your answer. Iron forms rust. Rusting is prevented by coating iron with zinc. Name the substances that react with iron to form rust. Name the process in which zinc is used to coat iron to prevent rusting. Explain how the coating of zinc prevents rusting if the zinc is not scratched. When zinc is scratched the iron becomes exposed. Explain how the zinc continues to prevent rusting. 
0620_w23_qp_43
THEORY
2023
Paper 4, Variant 3
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Aluminium is extracted from its ore. The ore is converted into pure aluminiumoxide, which then undergoes electrolysis as shown. + + + – anodes power supply electrolyte molten aluminium wires cathode Name an ore of aluminium. What is meant by the term electrolysis? Aluminiumoxide has a melting point of about 2000 °C, but the electrolysis process operates at about 900 °C. Name the compound added to aluminiumoxide to reduce the operating temperature. Suggest one benefit to the environment of reducing the operating temperature. Write the ionic half-equation for the reaction taking place at: the negative electrode the positive electrode  Explain why the anodes need frequent replacement. Aluminiumoxide reacts with acids and with alkalis. What term is used to describe an oxide that reacts with acids and with alkalis? Aluminiumoxide reacts with dilute sulfuric acid to form a salt. State the name and write the formula of the salt formed. name formula  Aluminiumoxide reacts with dilute sodiumhydroxide to form a salt and one other product. Name the other product. Aluminiumhydroxide, Al (OH)3, decomposes when heated to form aluminiumoxide and water. Write the chemical equation for this reaction. Suggest the names of two other aluminium compounds that decompose when heated to form aluminiumoxide. 
0620_m20_qp_42
THEORY
2020
Paper 4, Variant 2
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