9. Metals
A section of Chemistry, 0620
Listing 10 of 1272 questions
For Examiner's Use Strontium and zinc are both metals with a valency of 2. Strontium is more reactive than zinc. Its chemistry is similar to that of calcium. Complete the following table that shows the number of protons, electrons and neutrons in each particle. particle protons electrons neutrons 88Sr 90Sr 65Zn2+ Explain why 88Sr and 90Sr are isotopes. Complete the electron distribution of an atom of strontium. + + + + The major ore of zinc is zinc blende, ZnS. Describe how zinc is extracted from zinc blende. Give a use of zinc. For Examiner's Use The major ore of strontium is its carbonate, SrCO3. Strontium is extracted by the electrolysis of its molten chloride. Name the reagent that will react with the carbonate to form the chloride. The electrolysis of molten strontium chloride produces strontium metal and chlorine. Write ionic equations for the reactions at the electrodes. negative electrode positive electrode One of the products of the electrolysis of concentrated aqueous strontium chloride is chlorine. Name the other two. Both metals react with water. Write a word equation for the reaction of zinc and water and state the reaction conditions. word equation conditions Write an equation for the reaction of strontium with water and give the reaction condition. equation condition
0620_w05_qp_3
THEORY
2005
Paper 3, Variant 0
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Use When Group I elements react with water, hydrogen gas is given off. The diagram shows the reaction of lithium, potassium and sodium with water. A B C Which one of these elements A, B or C is lithium? Balance the equation for the reaction of sodium with water by completing the left- hand side. Na + H2O 2NaOH + H2 Apart from fizzing, describe two things that you would see when sodium reacts with water. After the sodium had reacted with the water, the solution was tested with red litmus paper. What colour did the litmus paper turn? Give a reason for your answer. colour reason Examiner's Use Which of the following statements about sodium are true? Tick two boxes. It is made by reducing sodium oxide with carbon. It reacts with chlorine to form sodium chloride. It reacts readily with oxygen. It only conducts electricity when molten. Rubidium also reacts with water. How does the speed of reaction of rubidium with water compare with that of potassium with water? Sodium has only one stable isotope whereas potassium has several isotopes. What do you understand by the term isotopes? How many protons does sodium have in its nucleus? Use the Periodic Table to help you. How many electrons are there in an atom of potassium? Uranium has many isotopes. One of these is uranium-235 (235U). What is the main use of this isotope of uranium?
0620_w06_qp_2
THEORY
2006
Paper 2, Variant 0
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Use The diagram shows a bottle of mineral water. top made of polylabel bottle made of polyThe polytop is made by polymerising propene molecules, CH3CH=CH2. Which one of the following best describes the propene molecules in this reaction? Put a ring around the correct answer. alkanes monomers polymers products salts State the name of the homologous series to which propene belongs. Propene is an unsaturated hydrocarbon. State the meaning of the following terms. unsaturated hydrocarbon Describe a chemical test to distinguish between an unsaturated hydrocarbon and a saturated hydrocarbon. State the results. test result with saturated hydrocarbon result with unsaturated hydrocarbon Examiner's Use The polybottle is made by polymerising ethene. nCH2=CH2 —CH2–CH2—n ( ) Complete the following sentence about this reaction by filling in the blank space. The formation of polyis an example of an polymerisation reaction. The label on the bottle lists the concentration of ions dissolved in the water in milligrams per litre. concentration of ions in milligrams per litre calcium nitrate chloride potassium 0.5 hydrogencarbonate sodium 4.5 magnesium sulphate State the name of two negative ions which appear in this list. Which metal ion in this list is present in the highest concentration? Calculate the amount of magnesium ions in 5 litres of this mineral water. Which ion in the list reacts with aqueous silver nitrate to give a white precipitate? Which ion in the list gives off ammonia when warmed with sodium hydroxide and aluminium foil? Complete the equation to show the formation of a potassium ion from a potassium atom. K → K+ + Examiner's Use The pH of the mineral water is 7.8. Which one of the following best describes this pH? Tick one box. slightly acidic slightly alkaline neutral very acidic very alkaline Pure water can be obtained by distilling the mineral water using the apparatus shown below. heat flask mineral water beaker A State the name of the piece of apparatus labelled A. Where does the pure water collect? How does the boiling point of the mineral water in the flask compare with the boiling point of pure water? Examiner's Use The diagram shows how mineral water is formed. Mineral water contains no bacteria or particles of earth. water drains through limestone mineral water surface water soil and bacteria water bacteria and soil particles limestone particles Use the diagram to explain how the water is purified from bacteria and particles of earth.
0620_w07_qp_2
THEORY
2007
Paper 2, Variant 0
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For Examiner's Use Magnesium reacts with bromine to form magnesium bromide. Magnesium bromide is an ionic compound. Draw a diagram that shows the formula of the compound, the charges on the ions and the arrangement of outer electrons around the negative ion. The electron distribution of a bromine atom is 2, 8, 18, 7. Use x to represent an electron from a magnesium atom. Use o to represent an electron from a bromine atom. In the lattice of magnesium bromide, the ratio of magnesium ions to bromide ions is 1:2. Explain the term lattice. Explain why the ratio of ions is 1:2. The reaction between magnesium and bromine is redox. Complete the sentences. Magnesium is the agent because it has electrons. Bromine has been because it has electrons.
0620_w07_qp_3
THEORY
2007
Paper 3, Variant 0
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For Examiner's Use Iron is extracted from its ore in a blast furnace. State the name of the ore from which iron is extracted. The diagram shows a blast furnace. A B C D coke + limestone + iron ore firebrick lining air in Which one of the raw materials is added to the blast furnace to help remove the impurities from the iron ore? The impurities are removed as a slag. Which letter on the diagram shows the slag? Carbon monoxide is formed in the blast furnace by reaction of coke with oxygen. Complete the equation for this reaction. C + CO State the adverse affect of carbon monoxide on human health. For Examiner's Use In the hottest regions of the blast furnace the following reaction takes place. Fe2O3 + 3C 2Fe + 3CO Which two of these sentences correctly describe this reaction? Tick two boxes. The iron oxide gets reduced. The reaction is a thermal decomposition. The carbon gets oxidised. The carbon gets reduced. Carbon neutralises the iron oxide. Aluminium cannot be extracted from aluminium oxide in a blast furnace. Explain why aluminium cannot be extracted in this way. State the name of the method used to extract aluminium from its oxide ore. State one use of aluminium.
0620_w08_qp_2
THEORY
2008
Paper 2, Variant 0
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Questions Discovered
1272