9. Metals
A section of Chemistry, 0620
Listing 10 of 1272 questions
Ethanol, C2H5OH, is a member of the alcohol homologous series. Give two characteristics of a homologous series. 1. 2. Draw the structure of ethanol showing all atoms and bonds. One use of ethanol is as a solvent. A pupil studied the reaction of iodine with zinc. She fi rst dissolved a few crystals of iodine in ethanol and recorded the temperature of the solution. The temperature was 18 °C. She then added excess powdered zinc and recorded the temperature again. The new temperature was 37 °C. temperature 18 °C iodine dissolved in ethanol temperature 37 °C excess zinc Is this reaction endothermic or exothermic? Explain your answer. What colour is solid iodine? The equation for the reaction is zinc + iodine → zinc iodide When the reaction is complete, the mixture contains zinc iodide dissolved in ethanol and unreacted zinc powder. Suggest how you can get crystals of zinc iodide from the reaction mixture. The diagram shows the structure of zinc iodide. I – I – I – I – I – I – Zn2+ Zn2+ Zn2+ Zn2+ Zn2+ I – I – I – I – What is the simplest formula for zinc iodide? The list below shows four different types of structure. What type of structure is zinc iodide? Put a ring around the correct answer. giant covalent giant ionic metallic molecular The equation for the reaction of zinc with dilute nitric acid is 4Zn + 10HNO3 → 4Zn(NO3)2 + NH4NO3 + 3H2O Write a word equation for this reaction. Describe a test for ammonium ions. test result
0620_w11_qp_23
THEORY
2011
Paper 2, Variant 3
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Antimony, Sb, is an element in Group V. The main ore of antimony is its sulfi de. The extraction of antimony is similar to that of zinc. Describe how each of these changes in the extraction of antimony is carried out. antimony sulfi de to antimony oxide antimony oxide to antimony Antimony oxide is a white powder which is insoluble in water. Describe how you would fi nd out if it is a basic, an acidic or an amphoteric oxide. When antimony chloride is added to water, a faint white precipitate forms and the mixture slowly goes cloudy. forward SbCl 3+ H2O2HCl + SbOCl colourless backward white Explain why after some time the appearance of the mixture remains unchanged. When a few drops of concentrated hydrochloric acid are added to the mixture, it changes to a colourless solution. Suggest an explanation. Suggest how you could make the colourless solution go cloudy.
0620_w11_qp_32
THEORY
2011
Paper 3, Variant 2
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The diagram below shows a kiln used for manufacturing lime. air blown in waste gases mixture of calcium carbonate and coke lime removed The reaction taking place in the kiln is calcium carbonate → calcium oxide + carbon dioxide State the name of a rock which is largely calcium carbonate. Explain why, at the end of the reaction, there is only lime left in the lime kiln. Coke is mainly carbon. Combustion of coke provides the heat for the reaction in the lime kiln. Write a symbol equation for the complete combustion of carbon in oxygen. Complete these sentences using words from the list below. air dioxide harmless hydrogenated limited monoxide poisonous water When carbon burns in a supply of , carbon is formed. This is a colourless gas which has no smell and is . Calcium carbonate reacts with hydrochloric acid to form carbon dioxide. Complete the word equation for this reaction. calcium carbonate carbon dioxide + + + → hydrochloric acid The speed of reaction of calcium carbonate with hydrochloric acid can be found using the apparatus shown below. cotton wool top pan balance hydrochloric acid small pieces of calcium carbonate Suggest how this apparatus can be used to fi nd the speed of this reaction. State how the speed of this reaction changes when the concentration of acid is increased, larger pieces of calcium carbonate are used, the temperature is increased.
0620_w12_qp_22
THEORY
2012
Paper 2, Variant 2
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The diagram below shows the apparatus used to electroplate a spoon with silver. rod of pure silver iron spoon aqueous silver nitrate + – battery Which is the anode? Put a ring around the correct answer in the list below. aqueous silver nitrate battery iron spoon rod of pure silver Describe what happens to the silver rod and the iron spoon during electroplating. silver rod iron spoon Why are metal objects electroplated? During the electroplating, silver atoms are converted to silver ions. Which one of the following statements about this reaction is correct? Tick one box. Silver atoms gain electrons. Silver atoms lose neutrons. Silver atoms lose electrons. Silver atoms gain protons. A student is given a slightly alkaline solution which contains chloride ions. Describe how the student could use aqueous silver nitrate to show that chloride ions are present in the solution. Silver is a shiny metallic solid with a high melting point and boiling point. Describe two other physical properties of silver.
0620_w12_qp_23
THEORY
2012
Paper 2, Variant 3
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The diagram shows a type of blast furnace built about 230 years ago. It was used to extract iron from iron ore. B A C D E Which letter on the diagram shows where the solid raw materials are put into the furnace, where air is blown into the furnace, where iron is removed from the furnace? Describe the main reactions occurring in a blast furnace for extracting iron from iron ore. In your answer, include ● the names of the raw materials used ● the main chemical reactions which occur ● relevant word equations. Iron reacts with hydrochloric acid. Complete the word equation for this reaction. iron + hydrochloric acid → + Iron(ions are formed in this reaction. Describe a test for iron(ions. test result Steel is an alloy of iron. Which one of the following statements about steel is correct? Tick one box. Steel is a mixture of iron with sulfur atoms. Stainless steel is commonly used to make car bodies. The physical properties of steel are exactly the same as those of iron. Steel is made by blowing oxygen through the molten iron obtained from the blast furnace.
0620_w12_qp_23
THEORY
2012
Paper 2, Variant 3
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Questions Discovered
1272