9.4. Reactivity series
A subsection of Chemistry, 0620, through 9. Metals
Listing 10 of 452 questions
The diagram shows part of the Periodic Table. Only some of the elements are shown. H Li C N O Na Al K Fe Co Ni Cu Zn Rb Cs Pb Answer the following questions using only the elements shown in the diagram. Each element may be used once, more than once or not at all. Which element has a giant covalent structure? Which element has the highest relative atomic mass? Which two elements are formed when molten aluminium oxide is electrolysed? and Which element in Group I reacts most rapidly with water? Which element oxidises in the presence of water to form rust? Which element burns in oxygen to form water? Rubidium reacts with oxygen to form rubidium oxide, Rb2O. Complete the symbol equation for this reaction. Rb + → 2Rb2O Lead compounds are atmospheric pollutants. State one adverse effect of lead compounds on health.
0620_s14_qp_22
THEORY
2014
Paper 2, Variant 2
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Calcium chloride, CaCl 2, is a salt. Suggest the name of an acid and a base that would react together to make calcium chloride. acid base Calcium chloride absorbs water vapour. When calcium chloride is heated, it loses its water of crystallisation. Complete the symbol equation for this reaction. Include the sign for a reversible reaction. CaCl 2.6H2O CaCl 2 + A student put some clean iron nails in two test-tubes, as shown in the diagram. She then left the test-tubes for several weeks. A B anhydrous calcium chloride CaCl 2 cotton wool cotton wool Explain why the nails in tube A did not rust but the nails in tube B rusted. Rust is hydrated iron(oxide. What does the (in iron(oxide refer to? Tick one box. the oxidation state of the oxygen the oxidation state of the iron the number of atoms of oxygen in a formula unit of iron(oxide the number of water molecules in the hydrated iron oxide The table describes the ease of reduction of some metal oxides with carbon monoxide. lead oxide moderate heating to about 200 °C needed iron oxide high temperature furnace at 750 °C needed magnesium oxide temperatures above 1000 °C needed zinc oxide very high temperature furnace at 900 °C needed Put these metals in order of their reactivity with carbon monoxide. least reactive most reactive Some metal oxides can be reduced by heating with hydrogen gas. CuO + H2 → Cu + H2O Explain how this equation shows that copper oxide is being reduced.
0620_s14_qp_23
THEORY
2014
Paper 2, Variant 3
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A student investigated the reaction of magnesium with dilute hydrochloric acid. Mg+ 2HCl → MgCl 2+ H2She measured the volume of gas given off at various times during the reaction. Complete the diagram of the apparatus she would use to measure the volume of the gas given off. Label the apparatus. flask hydrochloric acid magnesium ribbon The student carried out the reaction at 25 °C using magnesium ribbon. Her results are shown below. time / seconds volume of gas / cm3 How long does it take for the reaction to stop? seconds What is the volume of hydrogen made after 20 seconds? cm3 On the grid above, draw a line to show how the volume of gas changes when the experiment is carried out at 15 °C and all other conditions remain the same. The student repeated the experiment using magnesium powder. All other conditions remain the same. How does the rate of reaction with magnesium powder compare with the rate of reaction with magnesium ribbon? Draw a diagram to show the electron arrangement in a molecule of hydrogen. What type of bonding is present in a hydrogen molecule? Magnesium chloride is a salt. Magnesium sulfate is also a salt. Give the name of two compounds which react together to form magnesium sulfate. and
0620_s15_qp_21
THEORY
2015
Paper 2, Variant 1
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When sodium hydrogen carbonate is heated at 60 °C, carbon dioxide is given off. Complete the equation for this reaction. NaHCO3 Na2CO3 + CO2 + What type of chemical reaction is this? Tick one box. addition neutralisation oxidation thermal decomposition An aqueous solution of sodium hydrogen carbonate is slightly alkaline. Which one of the following pH values is slightly alkaline? Put a ring around the correct answer. pH 2 pH 7 pH 8 pH 13 Baking powder contains sodium hydrogen carbonate and crystals of a weak acid. When water is added, the acid reacts with the sodium hydrogen carbonate. Complete the general equation for the reaction of an acid with a carbonate. acid + carbonate carbon dioxide + + The diagram below shows bread baked with and without the addition of baking powder. All other conditions were kept the same. bread baked without baking powder bread baked with baking powder Why is the bread baked with baking powder bigger? Explain why the sodium hydrogen carbonate used in breadmaking must be pure. The diagram shows the arrangement of carbon dioxide molecules at –25 °C and 100 atmospheres pressure. represents a molecule of carbon dioxide What is the state of carbon dioxide under these conditions? Use the kinetic particle theory and the information in the diagram to explain your answer.
0620_s15_qp_22
THEORY
2015
Paper 2, Variant 2
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The table shows some properties of aluminium, copper, iron and sodium. metal electrical conductivity density in g / cm3 melting point / °C strength colour aluminium very good 2.70 fairly strong silver copper very good 8.92 very strong pink-brown iron good 7.86 very strong silver sodium good 0.97 weak silver Which two metals in the table are transition elements? Explain your answer by referring to a specific property of transition elements given in the table. Use the information in the table to suggest why overhead electricity cables are made from aluminium with a steel core, one reason why sodium is not used for electricity cables. Cobalt chloride is a transition element compound. Calcium chloride is a compound of a Group II metal. Describe one difference between cobalt chloride and calcium chloride. The table below shows some observations about the reaction of four metals with water or steam. metal observations aluminium reacts with steam when strongly heated lithium reacts rapidly with cold water magnesium reacts very slowly with cold water but rapidly with steam silver does not react with steam Place these metals in order of their reactivity. least reactive most reactive When iron is heated with steam, hydrogen is given off. 3Fe + 4H2O Fe3O4 + 4H2 What does the sign mean? Describe a test for hydrogen. test result Steel is an alloy of iron. Write about alloys of iron. In your answer refer to: • the meaning of the term alloy, • why alloys are used instead of pure iron, • an example of the use of an alloy of iron.
0620_s15_qp_22
THEORY
2015
Paper 2, Variant 2
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The reactions between metals and acids are redox reactions. Zn + 2H+ → Zn2+ + H2 Which change in the above reaction is oxidation, Zn to Zn2+ or 2H+ to H2? Give a reason for your choice. Which reactant in the above reaction is the oxidising agent? Give a reason for your choice. The rate of reaction between a metal and an acid can be investigated using the apparatus shown below. hydrochloric acid gas syringe 20 40 60 80 100 zinc foil A piece of zinc foil was added to 50 cm3 of hydrochloric acid, of concentration 2.0 mol / dm3. The acid was in excess. The hydrogen evolved was collected in the gas syringe and its volume measured every minute. The results were plotted and labelled as graph 1. volume time graph 2 (with copper) graph 1 The experiment was repeated to show that the reaction between zinc metal and hydrochloric acid is catalysed by copper. A small volume of aqueous copper(chloride was added to the acid before the zinc was added. The results of this experiment were plotted on the same grid and labelled as graph 2. Explain why the reaction mixture in the second experiment contains copper metal. Include an equation in your explanation. Explain how graph 2 shows that copper catalyses the reaction. If the fi rst experiment was repeated using ethanoic acid, CH3COOH, instead of hydrochloric acid, how and why would the graph be different from graph 1? Calculate the maximum mass of zinc which will react with 50 cm3 of hydrochloric acid, of concentration 2.0 mol / dm3. Zn + 2HCl → ZnCl 2 + H2 Show your working.
0620_s15_qp_31
THEORY
2015
Paper 3, Variant 1
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Questions Discovered
452