0620_w09_qp_2
A paper of Chemistry, 0620
Questions:
7
Year:
2009
Paper:
2
Variant:
0
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1
For Examiner's Use The list shows some non-metallic elements. bromine carbon fluorine krypton nitrogen oxygen Which two elements in the list are in the same Group of the Periodic Table? and Which element in the list has the highest proton number? Which two of these elements make up most of the air? and Bromine and fluorine form a compound with the formula BrF5. Calculate the relative molecular mass of BrF5. The diagram shows the structure of some compounds containing oxygen. K+ K+ K+ K+ O2– K+ O2– K+ K+ K+ K+ K+ K+ O2– K+ O2– K+ O2– A B C O C O D O N O O O S What type of oxide is compound C? For Examiner's Use Compound A is an atmospheric pollutant. Describe the source of compound A and state its effect on the environment. Source Effect on the environment In the presence of air, compound D reacts with water to form nitric acid. A student used the apparatus below to add an aqueous solution of nitric acid to an aqueous solution of potassium hydroxide. He added the acid until it was in excess. flask solution of nitric acid solution of potassium hydroxide burette Describe how the pH of the solution in the flask changes as the nitric acid is added until the acid is in excess. Describe how you can measure this pH change. The equation for the reaction is KOH + HNO3 → KNO3 + H2O State the name of the salt formed in this reaction.
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
11. Organic chemistry  →  11.5. Alkenes
9. Metals  →  9.4. Reactivity series
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2
For Examiner's Use Link the terms in the boxes on the left with the definitions on the right. The first one has been done for you. atom a substance containing different atoms or ions bonded together a substance made up of one type of atom the smallest part of an element which takes part in a chemical reaction the smallest group of covalently bonded atoms which can exist on its own a charged atom or group of atoms compound element ion molecule Which two of the following are mixtures? Tick two boxes. air graphite sodium chloride steel For Examiner's Use Draw a labelled diagram to show the atomic structure of an atom of helium. In your diagram include the structure of the nucleus. State a use for helium. Which one of these statements about helium is correct? helium is in Period 2 of the Periodic Table helium is a liquid at room temperature helium is unreactive helium has an incomplete outer shell of electrons
2. Atoms, elements and compounds  →  2.2. Atomic structure and the Periodic Table
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3
For Examiner's Use A student used the apparatus shown to calculate the energy released when ethanol burns. copper calorimeter water ethanol clamp polylid thermometer Draw the structure of ethanol showing all atoms and bonds. The energy released by the burning ethanol raises the temperature of the water in the copper calorimeter. Which one of these words best describes the energy change when ethanol burns? Put a ring around the correct answer. electrolytic electronic endothermic exothermic When 4.6 g of ethanol is burnt, 5.4 g of water is formed. Calculate the mass of water formed when 13.8 g of ethanol is burnt. For Examiner's Use Complete the equation for the combustion of ethanol. C2H5OH + 3O2 → CO2 + H2O The calorimeter is made of copper. Copper is a transition metal. State two properties which distinguish transition metals from Group I metals. When copper is left exposed to the air for some time, a coating of copper carbonate forms on its surface. The equation shows how copper carbonate reacts with hydrochloric acid. CuCO3+ 2HCl→ CuCl2+ CO2+ H2ODescribe two observations that can be made as this reaction happens. 1. 2. State the meaning of the symbol . The calorimeter lid is made of poly. Complete these sentences about polyusing words from the list. acids addition condensation ethane ethene monomers polymer Polyis a formed by the of ethene molecules. In this reaction the ethene molecules can be described as
11. Organic chemistry  →  11.6. Alcohols
9. Metals  →  9.4. Reactivity series
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4
For Examiner's Use Caesium is a metal in Group I of the Periodic Table. State two physical properties of caesium. State the number of electrons in the outer shell of a caesium atom. An isotope of caesium has a mass number of 133. What do you understand by the term isotope? Calculate the number of neutrons in this isotope of caesium. Complete the following table to estimate the boiling point of caesium and predict the reactivity of caesium with water. Group I metal density / g / cm3 boiling point / °C reactivity with water sodium 0.97 fizzes quickly, disappears gradually and does not burst into flame potassium 0.86 fizzes very quickly, disappears quickly and bursts into flame with a little spitting rubidium 1.53 fizzes extremely quickly, bursts into flame then spits violently and may explode caesium 1.88 For Examiner's Use The diagram shows the structure of caesium chloride. Cs+ Cl – Cs+ Cl – Cs+ Cl – Cs+ Cl – Cs+ Cl – Cs+ Cl – Cs+ Cl – Cs+ Cl – Cs+ Cl – Use this diagram to work out the simplest formula for caesium chloride. Caesium chloride dissolves in water to form a neutral solution. State the pH of a neutral solution. Describe a test for chloride ions. test result
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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5
For Examiner's Use Limonene is a colourless unsaturated hydrocarbon found in lemons. The structure of limonene is shown below. C C H C CH2 CH2 H2C H2C CH3 CH CH3 On the formula above, draw a circle around the bonds which make limonene an unsaturated compound. Write the molecular formula for a molecule of limonene. Describe the colour change which occurs when excess limonene is added to a few drops of bromine water. For Examiner's Use Limonene can be extracted from lemon peel by steam distillation. heat X B A C water lemon peel State the name of the pieces of apparatus labelled A, B and C. A B C At point X on the diagram, the water is in the form of steam. Describe the arrangement and the movement of the particles in steam. arrangement movement When limonene undergoes incomplete combustion, carbon monoxide is formed. What do you understand by the term incomplete combustion? State an adverse effect of carbon monoxide on health. For Examiner's Use The structures of some compounds found in plants are shown below. CO2H H H H H C C CO2H A B H C H H H H O H C C N H H H D Which one of these compounds is a carboxylic acid? Which one of these compounds is produced by the fermentation of glucose? Which one of these compounds is a hydrocarbon?
11. Organic chemistry  →  11.2. Naming organic compounds
11. Organic chemistry  →  11.5. Alkenes
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6
For Examiner's Use Aluminium is extracted by the electrolysis of aluminium oxide. A + – positive electrode electrolyte (aluminium oxide dissolved in molten cryolite) D C B Hydrated aluminium oxide is heated to produce pure aluminium oxide. Al2O3.3H2O → Al2O3 + 3H2O hydrated aluminium oxide What type of reaction is this? Put a ring around the correct answer. decompositon neutralisation oxidation reduction Explain why the electrolyte must be molten for electrolysis to occur. What is the purpose of the cryolite? Which letter in the diagram, A, B, C or D, represents the cathode? State the name of the products formed at the anode and cathode during this electrolysis. anode cathode Why do the anodes have to be renewed periodically? For Examiner's Use Complete the equation for the formation of aluminium from aluminium ions. Al 3+ + e− → Al State one use of aluminium.
9. Metals  →  9.6. Extraction of metals
4. Electrochemistry  →  4.1. Electrolysis
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7
For Examiner's Use The diagram shows an experiment to investigate the rusting of some iron nails. A air distilled water iron nail B air iron nail C air distilled water iron nail coated with zinc drying agent (calcium chloride) For each tube A, B and C predict whether the nails will rust. In each case give a reason. tube A: does the nail rust? reason tube B: does the nail rust? reason tube C: does the nail rust? reason Iron from the blast furnace contains impurities such as carbon, phosphorus, silicon and sulfur. Describe how the level of these impurities is decreased when steel is made from impure iron. State a use for stainless steel. For Examiner's Use Pure iron can be prepared by the reduction of iron(oxide, FeO. FeO + H2 → Fe + H2O Explain how this equation shows that the iron(oxide has been reduced. Iron(oxide reacts with acids. FeO + 2HCl → FeCl2 + H2O Write a word equation for this reaction.
9. Metals  →  9.5. Corrosion of metals
9. Metals  →  9.6. Extraction of metals
9. Metals  →  9.4. Reactivity series
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