General Certificate of Secondary Education March 2007 SCIENCE A CHY1B Unit C1b (Oils, Earth and Atmosphere) CHEMISTRY Unit C1b (Oils, Earth and Atmosphere) Monday 12 March 2007 Morning Session Time allowed: 30 minutes Instructions Fill in the boxes at the top of this page. Check that your name, candidate number and centre number are printed on the separate answer sheet. Check that the separate answer sheet has the title ‘Oils, Earth and Atmosphere’ printed on it. Attempt one Tier only, either the Foundation Tier or the Higher Tier. Make sure that you use the correct side of the separate answer sheet; the Foundation Tier is printed on one side and the Higher Tier on the other. Answer all the questions for the Tier you are attempting. Record your answers on the separate answer sheet only. Do all rough work in this book, not on your answer sheet. Instructions for recording answers Use a black ball-point pen. For each answer completely fill in the circle as shown: Do not extend beyond the circles. If you want to change your answer, you must cross out your original answer, as shown: If you change your mind about an answer you have crossed out and now want to choose it, draw a ring around the cross as shown: Information The maximum mark for this paper is 36. Advice Do not choose more responses than you are asked to. You will lose marks if you do. Make sure that you hand in both your answer sheet and this question paper at the end of the test. If you start to answer on the wrong side of the answer sheet by mistake, make sure that you cross out completely the work that is not to be marked. G/C22566/Mar07/CHY1B 6/6/6/6 CHY1B For this paper you must have: a black ball-point pen an objective test answer sheet. You may use a calculator. Surname Other Names Centre Number Candidate Number Candidate Signature2 You must do one Tier only, either the Foundation Tier or the Higher Tier. The Higher Tier starts on page 14 of this booklet. FOUNDATION TIER SECTION ONE Questions ONE to SIX. In these questions, match the letters, A, B, C and D, with the numbers 1– 4. Use each answer only once. Mark your choices on the answer sheet. QUESTION ONE This question is about hydrocarbons. Match words, A, B, C and D, with the numbers 1– 4 in the sentences. A alkanes B fuels C monomers D polymers Hydrocarbons are cracked to produce smaller molecules. Some of the products of cracking can be used in cars as . . . 1 . . . . The products of cracking include alkenes and saturated hydrocarbons called . . . 2 . . . . Alkenes can be used in reactions to make . . . 3 . . . such as poly(ethene) and poly(propene). In these reactions, many small molecules known as . . . 4 . . . join together to form very large molecules. G/C22566/Mar07/CHY1BTurn over 3 QUESTION TWO The pie charts show the gases in Earth’s early atmosphere and in Earth’s atmosphere today. Match gases, A, B, C and D, with the labels 1– 4 on the pie charts. A carbon dioxide B nitrogen C noble gases D oxygen Turn over for the next question Earth’s early atmosphere Earth’s atmosphere today Small quantities of other gases Small quantities of carbon dioxide, water vapour and ... 4 ... ... 1 ... ... 2 ... ... 3 ... G/C22566/Mar07/CHY1B4 QUESTION THREE This question is about four chemical substances. Match substances, A, B, C and D, with the numbers 1– 4 in the table. A ethanol B ethene C helium D poly(propene) QUESTION FOUR This question is about vegetable oils. Match substances, A, B, C and D, with the numbers 1– 4 in the sentences. A bromine B hydrogen C nickel D water Oils can form an emulsion when mixed with . . . 1 . . . and shaken. Unsaturated oils can react to turn red-brown . . . 2 . . . to colourless. Unsaturated oils are hardened when they react with . . . 3 . . . , and this reaction takes place at 60 °C with a . . . 4 . . . catalyst. What we can say about the substance 1 It is an unreactive gas. 2 It is produced when an alkene reacts with steam. 3 It is a polymer. 4 It belongs to a group of hydrocarbons with the general formula CnH2n G/C22566/Mar07/CHY1B5 QUESTION FIVE This question is about four processes. Match processes, A, B, C and D, with the numbers 1– 4 in the sentences. A analysis B combustion C condensation D convection Tectonic plates are moved by . . . 1 . . . in the mantle. Additives in food can be identified by chemical . . . 2 . . . . Oceans were formed by . . . 3 . . . of the water vapour in the atmosphere. The amount of carbon dioxide in the atmosphere has been increased by . . . 4 . . . of fossil fuels. Turn over for the next question Turn over G/C22566/Mar07/CHY1B6 QUESTION SIX The flow chart shows the stages in the breakdown of large hydrocarbon molecules. Match phrases, A, B, C and D, with the numbers 1– 4 in the flow chart. A hydrocarbons undergo thermal decomposition B hydrocarbons are heated C hydrocarbons vaporise D small hydrocarbon molecules large hydrocarbon molecules 12 hydrocarbon vapours passed over a hot catalyst 34 G/C22566/Mar07/CHY1B7 Turn over for the next question Turn over G/C22566/Mar07/CHY1B8 SECTION TWO Questions SEVEN to NINE. Each of these questions has four parts. In each part choose only one answer. Mark your choices on the answer sheet. QUESTION SEVEN Alfred Wegener was a German scientist who worked in the early part of the 20th century. His theory was that about 250 million years ago all the continents were connected together in a single ‘super continent’ which he called Pangaea. He suggested that the super continent split up and separate continents drifted apart. 7A One piece of evidence that Wegener used was that some continents . . . 1 have similar shapes. 2 have similar weather patterns. 3 have coastlines which fit quite closely together. 4 have similar vegetation. Pangaea G/C22566/Mar07/CHY1B9 7B When Wegener examined the African and South American continents, he found other evidence that these continents had once been connected. One piece of evidence suggested on this diagram is that the two continents have . . . 1 ancient rocks in matching positions. 2 similar patterns of fossils. 3 similar patterns of mountain belts. 4 similar sandstone rocks. 7C Many scientists did not accept Wegener’s theory because . . . 1 the continents did not have all the same animals. 2 the continents did not have all the same plants. 3 there was no way to explain how continents could move. 4 the Earth’s crust stayed the same. 7D About 50 years after Wegener put forward his theory, scientists began to accept the possibility that continents could move. This was because of evidence that . . . 1 the Earth’s crust was shrinking. 2 the Earth’s crust was cooling. 3 the Earth’s crust was separated into tectonic plates. 4 there was volcanic activity on most coastlines. Key Ancient rocks about 2000 million years old Mountain belts Shales with fossils Sandstone rocks Turn over G/C22566/Mar07/CHY1B10 QUESTION EIGHT In chromatography, substances can be identified by their Rf value. The Rf value can be calculated using the formula: Rf = distance moved by the substance distance moved by the solvent The Rf value for a substance is different in different solvents. Four red substances, A, B, C and D, were tested. The test was done using two different solvents, X and Y. For solvent X, the distances the substances moved and the distance the solvent moved are shown (in cm). For solvent Y, the Rf values are shown. 8A What is the Rf value of substance B in solvent X? 1 0.6 2 0.7 3 0.8 4 1.25 Solvent X A B C D Solvent Y A B C D 0.2 Rf values 0.2 0.6 0.8 Start line Distance moved by the solvent Distances moved in cm 3.0 3.5 5.0 cm 4.0 3.5 G/C22566/Mar07/CHY1B11 8B Which statement is true? 1 Substances A and B are the same. 2 Substances A and D are the same. 3 Substances B and D are the same. 4 The four substances are different. 8C Which statement about chromatography is true? 1 Chromatography works only on added artificial colouring. 2 Chromatography works only on added natural colouring. 3 Chromatography works only on natural colouring already in the food. 4 Chromatography works on any soluble colouring. 8D A red substance was tested. The chromatography strip using solvent X is shown. The Rf value in solvent Y is 0.2. Which statement is true? 1 The red substance could be A. 2 The red substance could be B. 3 The red substance could be C. 4 The red substance could be D. Solvent X 3.5 5.0 Distances in cm Turn over G/C22566/Mar07/CHY1B12 QUESTION NINE This information is on a packet of crisps. 9A What is the total amount of unsaturated fat in a packet of these crisps? 1 9.3 g 2 10.3 g 3 11.2 g 4 11.7 g 9B Unsaturated fats are different from saturated fats because unsaturated fats . . . 1 contain less iodine. 2 contain double carbon carbon bonds. 3 have higher melting points. 4 dissolve in water. 9C Approximately how much energy would be provided by 100 grams of these crisps? 1 400 kJ 2 530 kJ 3 720 kJ 4 1830 kJ Typical nutritional values per 34.5 gram packet of crisps Energy 183 kJ Carbohydrate 17.1 grams Fat – saturates 0.9 grams monounsaturates 9.3 grams polyunsaturates 1.0 grams Salt 0.5 grams G/C22566/Mar07/CHY1B13 9D Using your knowledge of a healthy diet and this information, it is fair to deduce that . . . 1 more salt should be added to each packet of crisps. 2 adults should eat at least one packet of crisps each day. 3 adults should not eat crisps. 4 it is unnecessary to add salt to crisps. END OF TEST a packet of crisps contains 0.5 g of salt a slice of bread contains about 0.5 g of salt many processed foods contain salt the guideline daily amount of salt for an adult is 6.0 g G/C22566/Mar07/CHY1B14 You must do one Tier only, either the Foundation Tier or the Higher Tier. The Foundation Tier is earlier in this booklet. HIGHER TIER SECTION ONE Questions ONE and TWO. In these questions, match the letters, A, B, C and D, with the numbers 1– 4. Use each answer only once. Mark your choices on the answer sheet. QUESTION ONE The flow chart shows the stages in the breakdown of large hydrocarbon molecules. Match phrases, A, B, C and D, with the numbers 1– 4 in the flow chart. A hydrocarbons undergo thermal decomposition B hydrocarbons are heated C hydrocarbons vaporise D small hydrocarbon molecules large hydrocarbon molecules 12 hydrocarbon vapours passed over a hot catalyst 34 G/C22566/Mar07/CHY1B15 QUESTION TWO This question is about the formulae for four hydrocarbon compounds. Match formulae, A, B, C and D, with the numbers 1– 4 in the table. Turn over for the next question Hydrocarbon compound Description 1 It has the molecular formula C3H8 2 It is the hydrocarbon with the smallest molecules. 3 It is an unsaturated hydrocarbon. 4 It is part of a polymer. HHCA H H C HHC H HHC HC HHC H H HHC HHC BD HHC HCH3 C HHC HCH3 C HHC HCH3 C Turn over G/C22566/Mar07/CHY1B16 SECTION TWO Questions THREE to NINE. Each of these questions has four parts. In each part choose only one answer. Mark your choices on the answer sheet. QUESTION THREE In chromatography, substances can be identified by their Rf value. The Rf value can be calculated using the formula: Rf = distance moved by the substance distance moved by the solvent The Rf value for a substance is different in different solvents. Four red substances, A, B, C and D, were tested. The test was done using two different solvents, X and Y. For solvent X, the distances the substances moved and the distance the solvent moved are shown (in cm). For solvent Y, the Rf values are shown. 3A What is the Rf value of substance B in solvent X? 1 0.6 2 0.7 3 0.8 4 1.25 Solvent X A B C D Solvent Y A B C D 0.2 Rf values 0.2 0.6 0.8 Start line Distance moved by the solvent Distances moved in cm 3.0 3.5 5.0 cm 4.0 3.5 G/C22566/Mar07/CHY1B17 3B Which statement is true? 1 Substances A and B are the same. 2 Substances A and D are the same. 3 Substances B and D are the same. 4 The four substances are different. 3C Which statement about chromotography is true? 1 Chromatography works only on added artificial colouring. 2 Chromatography works only on added natural colouring. 3 Chromatography works only on natural colouring already in the food. 4 Chromatography works on any soluble colouring. 3D A red substance was tested. The chromatography strip using solvent X is shown. The Rf value in solvent Y is 0.2. Which statement is true? 1 The red substance could be A. 2 The red substance could be B. 3 The red substance could be C. 4 The red substance could be D. Solvent X 3.5 5.0 Distances in cm Turn over G/C22566/Mar07/CHY1B18 QUESTION FOUR This information is on a packet of crisps. 4A What is the total amount of unsaturated fat in a packet of these crisps? 1 9.3 g 2 10.3 g 3 11.2 g 4 11.7 g 4B Unsaturated fats are different from saturated fats because unsaturated fats . . . 1 contain less iodine. 2 contain double carbon carbon bonds. 3 have higher melting points. 4 dissolve in water. 4C Approximately how much energy would be provided by 100 grams of these crisps? 1 400 kJ 2 530 kJ 3 720 kJ 4 1830 kJ Typical nutritional values per 34.5 gram packet of crisps Energy 183 kJ Carbohydrate 17.1 grams Fat – saturates 0.9 grams monounsaturates 9.3 grams polyunsaturates 1.0 grams Salt 0.5 grams G/C22566/Mar07/CHY1B19 4D Using your knowledge of a healthy diet and this information, it is fair to deduce that . . . 1 more salt should be added to each packet of crisps. 2 adults should eat at least one packet of crisps each day. 3 adults should not eat crisps. 4 it is unnecessary to add salt to crisps. Turn over for the next question a packet of crisps contains 0.5 g of salt a slice of bread contains about 0.5 g of salt many processed foods contain salt the guideline daily amount of salt for an adult is 6.0 g Turn over G/C22566/Mar07/CHY1B20 QUESTION FIVE The diagram shows the layered structure of the Earth. 5A The middle layer is called the . . . 1 atmosphere. 2 lava. 3 magma. 4 mantle. 5B The material in the middle layer is moving slowly. The movement is caused by . . . 1 the rotation of the Earth. 2 the drifting tectonic plates. 3 the cooling of the Earth. 4 heat from natural radioactive processes. 5C Mountains on the Earth’s surface are caused by large-scale movements of the Earth’s crust but scientists used to believe that they were caused by . . . 1 the movement of low density rocks above those that were more dense. 2 the activity of volcanoes. 3 shrinking of the crust after it was formed. 4 weathering and erosion. Middle layer Crust Core G/C22566/Mar07/CHY1B21 5D Much of the carbon dioxide that was present in Earth’s early atmosphere is now locked up in . . . 1 fossil fuels and sedimentary carbonate rocks. 2 volcanic rocks and fossil fuels. 3 metal ores and sedimentary carbonate rocks. 4 landfill sites and volcanic rocks. Turn over for the next question Turn over G/C22566/Mar07/CHY1B22 QUESTION SIX Large hydrocarbon molecules can be broken down, by cracking, to produce smaller molecules. An example of cracking is shown below: C14H30 C7H16 + C3H6 + 2C2H4 large hydrocarbon molecule small hydrocarbon molecules 6A Which of the products of the cracking reaction could form polymers? 1 C7H16 and C3H6 2 C7H16 and C2H4 3 C3H6 and C2H4 4 C7H16 only 6B The hydrocarbon with the formula C2H4 is . . . 1 ethane. 2 ethene. 3 ethanol. 4 propene. G/C22566/Mar07/CHY1B23 6C The hydrocarbon C2H4 can be represented as . . . 6D The general formula for the alkenes is . . . 1 CnHn 2 CnH2n 3 CnH2n+2 4 C2nHn Turn over for the next question HHC H H C 1 HHC HHC 2 HHC HHC 3 HHC HHC 4 Turn over G/C22566/Mar07/CHY1B24 QUESTION SEVEN The map gives some information about tectonic plates. 7A Why do we have only a few earthquakes in Britain? 1 Britain lies on the Eurasian plate. 2 Britain is not close to a plate boundary. 3 The Earth’s crust around Britain is very thick. 4 The Earth’s crust around Britain is not shrinking. 7B Turkey has a lot of earthquakes. People are not sure when the next one will happen because . . . 1 earthquakes occur in five or ten year cycles. 2 earthquakes occur only in mining areas. 3 scientists cannot accurately predict when an earthquake will occur. 4 earthquakes occur only when there is oil exploration. Iceland Britain Germany Plate movement Edges of the tectonic plates Sweden Turkey Key G/C22566/Mar07/CHY1B25 7C Approximately how far will the tectonic plates move in 1000 years? 1 a few centimetres 2 50 centimetres 3 50 metres 4 50 kilometres 7D In which of these countries would you most expect volcanic eruptions? 1 Britain 2 Iceland 3 Sweden 4 Germany Turn over for the next question Turn over G/C22566/Mar07/CHY1B26 QUESTION EIGHT Window frames for double glazing can be made from the plastic PVC, poly(vinyl chloride). Poly(vinyl chloride) is made from the polymerisation of vinyl chloride molecules which have the structure: 8A Vinyl chloride molecules can be described as . . . 1 alkenes. 2 polymers. 3 saturated. 4 unsaturated. 8B Vinyl chloride belongs to a family of chemicals that have the general formula . . . 1 CnHCl 2 CnHn–1Cl 3 CnHn+1Cl 4 CnH2n−1Cl 8C In the polymerisation process, vinyl chloride molecules are . . . 1 catalysts. 2 monomers. 3 additives. 4 emulsifiers. HHC HCl C G/C22566/Mar07/CHY1B27 8D PVC window frames do not need much maintenance because they are . . . 1 cheap to replace. 2 easily painted. 3 non-biodegradable. 4 rigid. Turn over for the next question Turn over G/C22566/Mar07/CHY1B28 QUESTION NINE Read this extract from a magazine article. 9A The main advantage of using biodiesel instead of petroleum diesel is that . . . 1 it does not cause any damage to engines. 2 it guarantees the soap industry a plentiful supply of glycerine. 3 it increases the amount of carbon dioxide released into the atmosphere. 4 it is a renewable fuel. 9B From the information given, it is possible to conclude that biodiesel will contribute to . . . 1 a decrease in acid rain formation. 2 an increase in fog formation. 3 a decrease in soap production. 4 a reduction in global warming. BIODIESEL Biodiesel is a fuel made by the chemical reaction of alcohol with vegetable oils such as soya bean oil. This process also produces glycerine which is used in soap making. Biodiesel can be used in engines which normally run on petroleum diesel. Biodiesel can be mixed with petroleum diesel in any proportions. Biodiesel is biodegradable and contains very little sulfur. The complete combustion of biodiesel forms more carbon dioxide, less carbon monoxide and much less particulate, smoke-type emissions than petroleum diesel. Some of the disadvantages of biodiesel include attacking engine hoses that were intended for a different fuel and loosening deposits within the engine left from previous fuels which can cause blockages. G/C22566/Mar07/CHY1B29 9C Which one of the following is a correct statement? 1 Biodiesel production will eventually make the distillation of crude oil unnecessary. 2 During combustion, fewer toxic emissions are produced by petroleum diesel than by biodiesel. 3 Plants used to make biodiesel use up carbon dioxide as they grow, so offsetting the carbon dioxide produced when the fuel burns. 4 There is nothing to limit the amount of crops a country can grow economically each year to produce biodiesel. 9D Which of the following statements about biodiesel compared with petroleum diesel is not based on scientific measurements? 1 Both the fuel and its combustion products are less carcinogenic than ordinary diesel. 2 For transportation, biodiesel is classed as less flammable than petroleum diesel. 3 The exhaust gases from a biodiesel-fuelled engine contain less unburnt hydrocarbons. 4 Biodiesel has a much more pleasant odour than petroleum diesel. END OF TEST G/C22566/Mar07/CHY1B30 There are no questions printed on this page G/C22566/Mar07/CHY1B31 There are no questions printed on this page G/C22566/Mar07/CHY1B32 There are no questions printed on this page G/C22566/Mar07/CHY1B Copyright © 2007 AQA and its licensors. All rights reserved.