0620_w21_qp_41
A paper of Chemistry, 0620
Questions:
5
Year:
2021
Paper:
4
Variant:
1
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1
Some elements are shown in the order they appear in the reactivity series. The most reactive element is at the top. sodium calcium magnesium aluminium zinc iron hydrogen copper Answer the questions using the list of elements. Each element may be used once, more than once or not at all. Identify: a non-metal a metal which is stored under oil the main component of steel a metal with three electrons in the outer shell of its atoms a metal found in brass a metal that forms chlorides of the type XCl 2 and XCl 3. Name the main ores of: zinc aluminium. In an experiment, a sample of aluminium appeared less reactive than expected. Explain why. Name two metals from the list which are extracted by reduction of their ores using carbon.  When zinc granules are added to aqueous copper(sulfate, a reaction occurs. During the reaction, a red-pink solid is formed and the solution becomes colourless. Name the red-pink solid. Name the colourless solution. Explain, in terms of particles, why the rate of this reaction increases when the temperature is increased. Suggest two other ways of increasing the rate of this reaction.  
9. Metals  →  9.4. Reactivity series
9. Metals  →  9.6. Extraction of metals
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2
This question is about copper and its compounds. Copper has two different naturally occurring atoms, 63Cu and 65Cu. State the term used for atoms of the same element with different nucleon numbers. The atomic number of copper is 29. Complete the table to show the number of protons, neutrons and electrons in the particles of copper shown. 63Cu 65Cu2+ protons neutrons electrons  Relative atomic mass is the average mass of naturally occurring atoms of an element. The percentage of the naturally occurring atoms in a sample of copper is shown. 63Cu 65Cu 70% 30% Deduce the relative atomic mass of copper in this sample. Give your answer to one decimal place.  relative atomic mass = Anhydrous copper(sulfate is used to test for the presence of water. When this test is positive, hydrated copper(sulfate is formed. State the colour change seen during this test. from to Complete the chemical equation to show the reaction that takes place. CuSO4 + CuSO4•5H2O State how hydrated copper(sulfate can be turned back into anhydrous copper(sulfate. Describe a test for pure water. Aqueous copper(sulfate contains Cu2+ions. Describe what is seen when aqueous copper(sulfate is added to aqueous sodiumhydroxide, NaOH. Write the ionic equation for the reaction between aqueous copper(sulfate and aqueous sodiumhydroxide. Include state symbols. When solid copper(nitrate is heated copper(oxide, nitrogen dioxide and oxygen are formed. 2Cu(NO3)2 → 2CuO + 4NO2 + O2 Calculate the volume of nitrogendioxide formed at room temperature and pressure when 4.7 g of Cu(NO3)2 is heated. Use the following steps: ● calculate the mass of one mole of Cu(NO3)2  g ● calculate the number of moles of Cu(NO3)2 used  moles ● determine the number of moles of nitrogendioxide formed  moles ● calculate the volume of nitrogendioxide formed at room temperature and pressure.  dm3  Write the chemical equation to show the action of heat on sodium nitrate, NaNO3. 
4. Electrochemistry  →  4.1. Electrolysis
10. Chemistry of the environment  →  10.1. Water
6. Chemical reactions  →  6.3. Reversible reactions and equilibrium
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3
This question is about electrolysis. Concentrated hydrochloricacid is electrolysed using the apparatus shown. concentrated hydrochloric acid carbon electrodes wire + – Chloride ions are discharged at the anode. Complete the ionic half-equation for this reaction. Cl –→ + e– State whether oxidation or reduction takes place. Explain your answer. Describe what is seen at the cathode. Write the ionic half-equation for the reaction at the cathode. The pH of the electrolyte is measured throughout the experiment. Suggest the pH of the electrolyte at the beginning of the experiment. State how the pH changes, if at all, during the experiment. Explain your answer. The electrolysis is repeated using molten lead(bromide. Describe what is seen at the: ● cathode ● anode.  State two properties of graphite which make it suitable for use as an electrode.  
4. Electrochemistry  →  4.1. Electrolysis
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4
Chalcopyrite, FeCuS2, is used in the manufacture of sulfuricacid in the Contact process. In the first stage of the process, chalcopyrite reacts with oxygen in the air to produce sulfurdioxide, SO2, iron(oxide and copper(oxide. Complete the chemical equation for the reaction of FeCuS2 with oxygen. 4FeCuS2 + 13O2 → + +  Sulfurdioxide is then converted to sulfurtrioxide. 2SO2 + O2 2SO3 The reaction is exothermic. It is also an equilibrium. State two features of an equilibrium.  State the temperature and pressure used in this reaction. Include units. ● temperature ● pressure  Name the catalyst used. Explain why a catalyst is used. Describe and explain, in terms of equilibrium, what happens when the temperature is increased. Concentrated sulfuricacid is a dehydrating agent. When glucose is dehydrated, carbon and one other product are formed. Complete the equation to show the dehydration of glucose, C6H12O6. C6H12O6 → C +  
6. Chemical reactions  →  6.3. Reversible reactions and equilibrium
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5
Alkenes and carboxylicacids are both families of similar compounds with similar chemical properties. Alkenes and carboxylicacids have different reactions. State the term used for a ‘family’ of similar compounds. State the general formula of alkenes. The structure of but-2-ene is shown. H C H H C H C C H H H H But-2-ene reacts with aqueous bromine in an addition reaction. Describe the colour change seen when but-2-ene is added to aqueous bromine. from to State what is meant by the term addition reaction. Write the chemical equation for the reaction between but-2-ene and bromine. But-2-ene forms a polymer. Suggest the name of the polymer formed from but-2-ene. Name and draw a structural isomer of but-2-ene. Show all of the atoms and all of the bonds. name structure  Butanoic acid, CH3CH2CH2COOH, is a carboxylicacid. Deduce the empirical formula of butanoicacid. Complete the chemical equation for the reaction of butanoicacid and sodiumcarbonate, Na2CO3. 2CH3CH2CH2COOH + Na2CO3 → + +  Butanoicacid reacts with methanol to form an organic compound and water. ● Name the organic compound formed. ● Draw the structure of the organic compound formed. Show all of the atoms and all of the bonds.  
11. Organic chemistry  →  11.5. Alkenes
11. Organic chemistry  →  11.2. Naming organic compounds
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