-1- IGCSE Co-ordinated Sciences Post-Mock Revision Questions Chemistry Portion Name: …………………………………………………………… COORDINATED SCIENCE – CHEMISTRY PORTION Paper 1 Multiple Choice 0654/1 January 2012 45 minutes Additional Materials: Multiple Choice Answer Sheet Soft clean eraser Soft pencil (type B or HB is recommended) READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, Centre number and candidate number on the Answer Sheet in the spaces provided unless this has been done for you. There are forty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. -2- 1 A drop of liquid bromine is placed in the bottom of a gas jar. Brown fumes of bromine vapour slowly spread through the covered gas jar. Why does this happen? 2 A Bromine vapour is less dense than air. B Bromine molecules and the molecules in air are always moving around. C Bromine molecules are smaller than the molecules in air. D Bromine molecules move faster than the molecules in air. Copper (II) sulfate crystals are separated from sand using the four processes listed below. In which order are these processes used? 3 In which pair is each substance a mixture? A air and water B limewater and water C quicklime and limewater D sea water and air -3- 4 The diagram shows a chromatogram of several inks. Which statement is correct? 5 A Black ink can be made by mixing green, red and yellow inks. B Brown ink can be made by mixing blue and red inks. C Yellow ink can be used to make brown ink. D Yellow ink may be present in green ink. Hydrogen can form both H+ ions and H– ions. Which one of the statements below is correct? A An H+ ion has more protons than an H– ion. B An H+ ion has no electrons. C An H– ion has one more electron than an H+ ion. D An H– ion is formed when a hydrogen atom loses an electron. -4- 6 7 In which of the following is there a lattice of positive ions in a ‘sea of electrons’? A liquid potassium chloride B sand C solid graphite D solid magnesium The diagram shows the molecule ethyl propanoate. How many bonding pairs of electrons are there in the molecule? A 13 8 B 16 C 17 The diagram shows the structures of diamond and graphite. Which property do these substances have in common? A They are giant structures. B They can act as lubricants. C They can conduct electricity. D They contain only covalent bonds. D 20 -5- 9. The equation for the reaction between copper and nitric acid is shown. vCu + wHNO3 → xCu(NO3)2 + yNO + zH2O v, w, x, y and z are whole numbers. Which values of v, w, x, y and z balance the equation? 10 What is the mass of one mole of carbon-12? A 0.012 g 11 12 B 0.024 g C1g D 12 g What is the concentration of iodine molecules, I2, in a solution containing 2.54 g of iodine in 250 cm3 of solution? A 0.01 mol / cm3 B 0.02 mol / cm3 C 0.04 mol / cm3 D 0.08 mol / cm3 A dark, shiny solid, X, conducts electricity. Oxygen combines with X to form a gaseous oxide. What is X? A graphite B iodine C iron D lead -6- 13 The diagram shows the apparatus used to electrolyse lead (II) bromide using inert electrodes. Why does the lamp light up only when the lead (II) bromide is melted? 14 A Bromine atoms in the lead (II) bromide are converted to ions when it is melted. B Electrons flow through the lead (II) bromide when it is melted. C The ions in lead (II) bromide are free to move only when the solid is melted. D There are no ions in solid lead (II) bromide. The diagram shows a method used to electroplate a key with copper. Which aqueous solution is most suitable for the electrolyte? A copper (II) sulphate B ethanol C sodium hydroxide D sulphuric acid -7- 15 The table compares the strengths of the bonds for reactions of the type below. Which reaction is most exothermic? 16 17 In which process does an endothermic change take place? A combustion B evaporation C filtration D neutralization What is not an example of oxidation? A converting iron (III) salts into iron (II) salts B converting magnesium atoms into magnesium ions C dissolving of a copper anode during electrolysis D liberating chlorine from a chloride -8- 18 A student performs two reactions. reaction 1; 10 g of magnesium ribbon with excess 2.0 mol / dm3 dilute hydrochloric acid reaction 2; 5 g of magnesium powder with excess 2.0 mol / dm3 dilute hydrochloric acid In both experiments, the volume of hydrogen produced, V, is measured against time, t, and the results plotted graphically. Which set of graphs is correct? 19 The following changes could be made to the conditions in the reaction between zinc and hydrochloric acid. 1 increase in concentration of the acid 2 increase in particle size of the zinc 3 increase in pressure on the system 4 increase in temperature of the system Which pair of changes will increase the rate of reaction? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 -9- 20 Sodium hydroxide solution was added to dilute hydrochloric acid. The pH of the solution in the flask was measured at intervals until no further change of pH took place. What would be the pH change in this reaction? 21 A decrease to 1 B decrease to 7 C increase to 7 D increase to 12 Carbon and silicon are both in Group IV of the Periodic Table. Which statement is correct for both carbon dioxide and silicon dioxide? A They are acidic oxides. B They are readily soluble in water. C They contain ionic bonds. D They have giant molecular structures. - 10 - 22 A student mixed together aqueous solutions of Y and Z. A white precipitate formed. Which could not be solutions Y and Z? 23 The tests below were carried out on a solution containing ions of the metal X. What is metal X? 24 A calcium B iron C lead D zinc Which property is common to calcium, potassium and sodium? A Their atoms all lose two electrons when they form ions. B They all form carbonates which are insoluble in water. C They are all less dense than water. D They are all metallic. - 11 - 25 Which pair of properties are both correct for a typical transition element? 26 Which statement about the elements chlorine, bromine and iodine is correct? 27 A They are all gases at room temperature and pressure. B They are in the same period of the Periodic Table. C They become darker in colour from chlorine to bromine to iodine. D They possess one electron in the outermost shell. The list shows some properties of metals. 1 Metals are good conductors of electricity. 2 Metals form ions by the loss of electrons. 3 Metals have high melting points. Mercury is a metallic element. Which of these statements do not apply to mercury? A 1 only 28 B 1 and 2 C 2 and 3 D 3 only In the manufacture of iron, using a blast furnace, which reaction generates heat? A CaCO3 → CaO + CO2 B Fe2O3 + 3CO → 2Fe + 3CO2 C C + O2 → CO2 D C + CO2 → 2CO - 12 - 29 The steel bodies of cars can be protected from rusting by spraying them with zinc. Why is zinc used? 30 A Zinc does not react with acidic exhaust fumes. B Zinc forms a stable compound with iron. C Zinc has a high melting point. D Zinc is higher in the reactivity series than iron. The diagram shows processes that take place in the manufacture of ammonia. What are substances W and X and catalyst Y? 31 The gases coming from a car’s exhaust contain oxides of nitrogen. How are these oxides formed? A Nitrogen reacts with carbon dioxide. B Nitrogen reacts with carbon monoxide. C Nitrogen reacts with oxygen. D Nitrogen reacts with petrol. - 13 - 32 The diagram shows steel wool inside a test-tube. The test-tube is inverted in water, trapping air inside. What will be the water level inside the tube after several days? 33 34 In the Contact process, the sulfur trioxide formed is A passed into concentrated sulfuric acid. B passed into dilute sulfuric acid. C passed into oleum (H2S2O7). D passed into water. What is the concentration of hydrogen ions in 0.05 mol / dm3 sulfuric acid? A 0.025 g / dm3 B 0.05 g / dm3 C 0.10 g / dm3 D 2.0 g / dm3 - 14 - 35 When calcium carbonate is heated, compound X and a gas are formed. What is the name of X and what is its use? 36 Lime is used to treat an industrial waste. Which pH change occurs in the treatment? untreated waste → → treated waste A acidic B alkaline → acidic C alkaline → neutral D neutral → neutral acidic - 15 - 37 Useful fractions are obtained by the fractional distillation of petroleum. Which fraction is matched by its use? 38 The diagram shows the breakdown of an alkane to ethene. The ethene is then tested with aqueous bromine. Which information about ethene is correct? - 16 - 39 The structural formulae of some organic compounds are shown below. Which compounds are alcohols? A 1, 2, 3 and 4 40 B 1 and 2 only C 1, 2 and 3 only Which pair of macromolecules both contain the linkage shown? A fats and proteins B nylon and proteins C starch and sugars D Terylene and sugars D 4 only