0620_w12_qp_21
A paper of Chemistry, 0620
Questions:
7
Year:
2012
Paper:
2
Variant:
1
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1
For Examiner’s Use The diagram shows the structures of fi ve compounds, A, B, C, D and E, containing carbon. C C H H H H C H H C O H H H H C O C A B C O Cl Cl Cl Cl C D E H H H H Answer these questions using the letters A, B, C, D or E. Each compound can be used once, more than once or not at all. Which one of these compounds is an unsaturated hydrocarbon, is a product of the complete combustion of a hydrocarbon, belongs to the alcohol homologous series, is an alkane, is a product of respiration, is a product of fermentation? Write the molecular formula of compound C. Compound B is inert to most chemical reagents. It is made by reacting chlorine with carbon disulfi de in the presence of an aluminium chloride catalyst. What do you understand by the following terms? compound inert catalyst
11. Organic chemistry  →  11.2. Naming organic compounds
11. Organic chemistry  →  11.5. Alkenes
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2
For Examiner’s Use Hydrogen chloride, HCl, is an acidic gas. Draw a dot and cross diagram of a molecule of hydrogen chloride. Show only the outer electrons. Hydrogen chloride dissolves in water to form a solution of hydrochloric acid. A student titrated aqueous ammonia with hydrochloric acid using the apparatus shown below. B hydrochloric acid aqueous ammonia A State the name of the pieces of apparatus labelled A and B. A is a B is a Describe how the pH value of the solution in B changes as hydrochloric acid is added until the acid is in excess. For Examiner’s Use Complete the word and symbol equations for this reaction. ammonia + hydrochloric acid → + HCl → NH4Cl Aqueous ammonia is used to test for copper(ions. Describe what happens when you add aqueous ammonia to a solution of copper(sulfate until the aqueous ammonia is in excess.
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
9. Metals  →  9.4. Reactivity series
10. Chemistry of the environment  →  10.1. Water
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3
For Examiner’s Use The reactivity of different metal oxides was compared by heating them with metals in a crucible. heat mixture of metal oxide and metal The results are shown in the table below. mixture observations iron oxide + zinc reacts lead oxide + iron reacts magnesium oxide + zinc no reaction Use the results in the table to suggest the order of reactivity of the metals iron, lead, magnesium and zinc. most reactive least reactive Predict whether iron will react with zinc oxide. Explain your answer. Which two of the following statements about metals are correct? Tick two boxes. Metals conduct electricity and heat. All Group IV elements show metallic properties. Magnesium is extracted by heating its oxide with carbon. All metals have high densities. Iron is a transition element. For Examiner’s Use Sand and salt (sodium chloride) are both solids. Describe the arrangement and movement of the particles in a solid. arrangement movement Describe how you could separate the sand from a mixture of sand and salt. Give full details of how this is carried out. The diagram below shows the apparatus used to separate ethanol and water from a mixture of ethanol and water. heat ethanol and water fractionating column water out water in Complete the following sentences about this separation using words from the list below. condenser crystallisation distillation fl ask heavy higher lower solid volatile vapour Fractional is used to separate a mixture of water and ethanol. The temperature at the top of the fractionating column is than the temperature at the bottom. The more liquid evaporates and moves further up the column. It eventually reaches the where the changes to a liquid.
9. Metals  →  9.6. Extraction of metals
9. Metals  →  9.4. Reactivity series
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4
For Examiner’s Use Lithium has two naturally-occurring isotopes, Li and Li . What do you understand by the term isotope? Draw a labelled diagram to show the atomic structure of an atom of Li . Show the particles in the nucleus as well as the electrons. Lithium reacts with oxygen to form lithium oxide, Li2O. Complete the equation for this reaction. Li + → Li2O For Examiner’s Use Aqueous lithium chloride is electrolysed using the apparatus shown below. + – On the diagram above, label: ● the electrolyte ● the anode. What do you understand by the term aqueous? Explain why aqueous lithium chloride is able to conduct electricity.
4. Electrochemistry  →  4.1. Electrolysis
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
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5
For Examiner’s Use Match the fuel on the left with the information on the right. The fi rst one has been done for you. uranium-236 a fuel with a relative molecular mass of 2 hydrogen the main constituent of natural gas methane a nuclear ‘fuel’ fuel oil fuel for aircraft kerosene fuel for ships Two students investigated some fuels to fi nd which gave off the most energy. They tested four liquid fuels using the apparatus shown below. thermometer spirit burner copper can liquid fuel 100 g of water In each experiment, the amount of fuel burnt was the same. Suggest one other factor that should be kept the same in each experiment. The students used the thermometer to stir the water. Suggest why it is important to keep the water stirred. For Examiner’s Use The results are shown in the table below. fuel initial temperature of the water / °C fi nal temperature of the water / °C ethanol propanol paraffi n petroleum spirit Which fuel transfers the most energy to the water? Explain your answer. Air is needed for fuels to burn. The pie chart below shows the composition of the air. mainly argon A B State the name of gas A, gas B. Argon is a noble gas. State one use for argon. To which period in the Periodic Table does argon belong? Describe the chemical properties of argon.
11. Organic chemistry  →  11.3. Fuels
11. Organic chemistry  →  11.6. Alcohols
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
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6
For Examiner’s Use A student placed a crystal of silver nitrate and a crystal of potassium iodide in a dish of water. After an hour she observed that ● the crystals had disappeared, ● a yellow precipitate had appeared near the middle of the dish. at the start after an hour crystal of silver nitrate crystal of potassium iodide dish of water yellow precipitate Use your knowledge of the kinetic particle theory and reactions between ions to explain these observations. Potassium iodide reacts with aqueous chlorine. Complete the equation for this reaction. 2KI + → KCl + I2
1. States of matter  →  1.1. Solids, liquids and gases
9. Metals  →  9.4. Reactivity series
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7
For Examiner’s Use The diagram shows one molecule of sulfur. S S S S S S S S How many atoms are there in three molecules of sulfur? Calculate the relative molecular mass of sulfur. Explain how acid rain is formed when fossil fuels containing sulfur are burnt. In your answer, include ● the name of a fossil fuel which contains sulfur, ● the gas formed when sulfur burns, ● the reactions which lead to the formation of acid rain. Potassium sulfate can be used as a fertiliser. The potassium in this fertiliser is an important element for plant growth. Name two other elements, important for plant growth, which are present in most fertilisers. and Describe a test for sulfate ions. test result
6. Chemical reactions  →  6.3. Reversible reactions and equilibrium
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