9.6. Extraction of metals
A subsection of Chemistry, 0620, through 9. Metals
Listing 10 of 311 questions
The diagram shows a blast furnace for extracting iron. mixture of iron ore, coke and limestone (calcium carbonate) slag molten iron On the diagram write ● the letter A to show where air is blown into the furnace, ● the letter W to show where waste gases exit the furnace. How do you know from the information in the diagram that slag is less dense than molten iron? Limestone (calcium carbonate) is one of the raw materials added to the blast furnace. Calcium carbonate undergoes thermal decomposition in the blast furnace. What is meant by the term thermal decomposition? Complete the chemical equation for this reaction. CaCO3 CaO + A further reaction in the blast furnace involves calcium oxide, CaO. Describe this reaction and explain its importance. Pure iron can be prepared by electrolysis of an aqueous solution of a suitable iron(salt. Draw a labelled diagram of an electrolysis cell that could be used to carry out this reaction. In your diagram include ● the electrodes, ● the electrolyte, ● the power supply. State the name of an element that could be used for the electrodes. State one property that an electrode should have. Pure iron can also be prepared by the thermal decomposition of iron pentacarbonyl. The structure of iron pentacarbonyl is shown. Fe C C C C C O O O O O Write the formula for iron pentacarbonyl. The word equation for the reaction is shown. iron pentacarbonyl iron + carbon monoxide Explain why the gaseous product is hazardous. The rate of rusting of iron varies with pH and temperature. What two substances must be in contact with iron for it to rust? The graph shows the rate of rusting at different pH values and temperatures. mass of rust / g time / hours pH 4, 30 °C pH 4, 20 °C pH 7, 30 °C pH 8, 30 °C pH 7, 20 °C pH 8, 20 °C How do pH and temperature affect the rate of rusting? pH temperature
0620_m17_qp_32
THEORY
2017
Paper 3, Variant 2
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Iron is extracted by heating a mixture of coke , limestone and iron ore in air in a blast furnace. A diagram of the blast furnace is shown. coke + limestone + iron ore air in molten iron slag firebrick lining Name the ore of iron added to the blast furnace. The impurities in the iron ore are removed as slag. What information in the diagram shows that slag is less dense than molten iron? Which one of the substances added to the blast furnace helps to remove the impurities? Explain how it does this. substance explanation  Hot air is blown into the blast furnace. Explain why. The chemical equation for one of the reactions in the blast furnace is shown. Fe2O3 + 3CO → 2Fe + 3CO2 How does this equation show that Fe2O3 has been reduced? When 16.0 g of Fe2O3 react with excess carbonmonoxide, 11.2 g of iron are produced. Calculate the mass of iron produced when 4.0 g of Fe2O3 react with excess carbonmonoxide.  mass of iron = g An isotope of iron is shown. 58Fe Deduce the number of electrons, protons and neutrons in an atom of this isotope of iron. number of electrons number of protons number of neutrons  Iron is a transition element. Which two of these statements about iron are correct? Tick two boxes. Iron forms coloured compounds. Iron can act as a catalyst. Iron is brown when freshly cut. Iron has a low density. Iron has a low melting point.  
0620_m20_qp_32
THEORY
2020
Paper 3, Variant 2
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Questions Discovered
311