0620_s06_qp_3
A paper of Chemistry, 0620
Questions:
7
Year:
2006
Paper:
3
Variant:
0
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1
Use Iron is a transition element. Which of the following statements about transition elements are correct? Tick three boxes. The metals are highly coloured e.g. yellow, green, blue. The metals have low melting points. Their compounds are highly coloured. Their compounds are colourless. The elements and their compounds are often used as catalysts. They have more than one oxidation state. In which Period in the Periodic Table is iron to be found? Use the Periodic Table to work out the number of protons and the number of neutrons in one atom of iron. number of protons = number of neutrons = Iron is extracted in a blast furnace. The list below gives some of the substances used or formed in the extraction. carbon monoxide coke iron ore limestone slag Which substance is a mineral containing largely calcium carbonate? Which substance is formed when impurities in the ore react with calcium oxide? Which substance is also called hematite? Examiner's Use State two functions of the coke used in the blast furnace. Most of the iron is converted into mild steel or stainless steel. Give one use for each. mild steel stainless steel
9. Metals  →  9.6. Extraction of metals
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2
Use Some reactions of metals W, X, Y and Z are given below. metal reaction with water reaction with dilute hydrochloric acid W A few bubbles form slowly in cold water. Vigorous reaction. Gas given off. X Vigorous reaction. Metal melts. Gas given off. Explosive reaction. Should not be attempted. Y No reaction. No reaction. Z Does not react with cold water. Hot metal reacts with steam. Steady fizzing. Arrange these metals in order of reactivity. most reactive least reactive Which of these metals could be magnesium, copper? Examiner's Use The equation for the reaction of X with cold water is given below. 2X+ 2H2O2XOH+ H2Describe the test you would use to show that the gas evolved is hydrogen. How could you show that the water contained a compound of the type XOH? In which group of the Periodic Table does metal X belong? The ore of X is its chloride. Suggest how metal X could be extracted from its chloride.
9. Metals  →  9.4. Reactivity series
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
9. Metals  →  9.1. Properties of metals
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3
Use Four bottles were known to contain aqueous ammonia, dilute hydrochloric acid, sodium hydroxide solution and vinegar, which is dilute ethanoic acid. The bottles had lost their labels. The pH values of the four solutions were 1, 4, 10 and 13. Complete the table. solution pH aqueous ammonia dilute hydrochloric acid sodium hydroxide solution vinegar The following apparatus was set up to investigate the electrical conductivity of dilute acids. + _ carbon anode bulb/lamp carbon cathode dilute sulphuric acid bubbles of oxygen gas bubbles of hydrogen gas Dilute sulphuric acid is a strong acid. If it was replaced by a weak acid, what two differences in the observations would you expect to make? When nitric acid is added to water the following reaction occurs. HNO3 + H2O - NO + H3O+ Give the name and the formula of the particle which is transferred from nitric acid to water. name formula Examiner's Use This question is concerned with the following oxides. aluminium oxide Al2O3 calcium oxide CaO carbon dioxide CO2 carbon monoxide CO magnesium oxide MgO sulphur dioxide SO2 Which of the above oxides will react with hydrochloric acid but not with aqueous sodium hydroxide? Which of the above oxides will react with aqueous sodium hydroxide but not with hydrochloric acid? Which of the above oxides will react both with hydrochloric acid and with aqueous sodium hydroxide? Which of the above oxides will react neither with hydrochloric acid nor with aqueous sodium hydroxide?
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
9. Metals  →  9.4. Reactivity series
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4
Use The first three elements in Group IV are carbon, silicon, germanium. The element germanium has a diamond-type structure. Describe the structure of germanium. A diagram is acceptable. Unlike diamond, graphite is soft and is a good conductor of electricity. Explain why graphite has these properties. Give a use of graphite that depends on one of these properties. property use Carbon dioxide and silicon(oxide have similar formulae but different types of structure. Give the formulae of these oxides. How are their structures different? All these elements form compounds with hydrogen called hydrides. The saturated hydrides of carbon are the alkanes. Predict the formula of the hydride of germanium which contains two germanium atoms.
2. Atoms, elements and compounds  →  2.6. Giant covalent structures
8. The Periodic Table  →  8.1. Arrangement of elements
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5
Use Sulphuric acid is made by the Contact process in the following sequence of reactions. sulphur sulphur dioxide sulphur trioxide sulphuric acid How is sulphur dioxide made from sulphur? Sulphur dioxide has other uses. Why is it used in the manufacture of paper? How does it preserve food? The equation for a stage of the Contact process is 2SO2 + O2 2SO3 The percentage of sulphur trioxide in the equilibrium mixture varies with temperature. percentage of sulphur trioxide temperature How does the percentage of sulphur trioxide in the equilibrium mixture vary as the temperature increases? Circle the correct answer. increases stays the same decreases Is the forward reaction in the equilibrium 2SO2 + O2 2SO3 exothermic or endothermic? Give a reason for your choice. Examiner's Use Explain, mentioning both rate and percentage yield, why the temperature used in the Contact process is 450°C. Describe how the sulphur trioxide is changed into concentrated sulphuric acid.
6. Chemical reactions  →  6.3. Reversible reactions and equilibrium
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6
Use Exothermic reactions produce heat energy. An important fuel is methane, natural gas. The equation for its combustion is as follows. CH4 + 2O2 CO2 + 2H2O In chemical reactions bonds are broken and new bonds are formed. Using this reaction give an example of a bond that is broken, a bond that is formed. Explain, using the idea of bonds forming and breaking, why this reaction is exothermic, that is it produces heat energy. Some radioactive isotopes are used as nuclear fuels. Give the symbol and the nucleon number of an isotope that is used as a nuclear fuel. Give another use of radioactive isotopes. Examiner's Use Cell reactions are both exothermic and redox. They produce electrical energy as well as heat energy. The diagram shows a simple cell. V zinc electrode becomes thinner iron electrode bubbles of hydrogen form dilute sulphuric acid voltmeter Which substance in this cell is the reductant and which ion is the oxidant? reductant oxidant How could the voltage of this cell be increased? What is the important large scale use, relating to iron and steel, of this type of cell reaction? Examiner's Use Cells can be set up with inert electrodes and the electrolytes as oxidant and reductant. V voltmeter carbon electrode carbon electrode potassium manganate(potassium iodide salt bridge (allows ions to move from one beaker to another) electron flow The potassium manganate(is the oxidant and the potassium iodide is the reductant. Describe the colour change that would be observed in the left hand beaker. Write an ionic equation for the reaction in the right hand beaker.
5. Chemical energetics  →  5.1. Exothermic and endothermic reactions
6. Chemical reactions  →  6.4. Redox
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7
Use The fractional distillation of crude oil usually produces large quantities of the heavier fractions. The market demand is for the lighter fractions and for the more reactive alkenes. The heavier fractions are cracked to form smaller alkanes and alkenes as in the following example. C8H18 C4H10 + C4H8 octane butane butenes Write a different equation for the cracking of octane. C8H18 + The cracking of octane can produce isomers with the molecular formula C4H8. Draw the structural formulae of two of these isomers. Give the essential condition for the reaction between chlorine and butane. What type of reaction is this? This reaction produces a mixture of products. Give the names of two products that contain four carbon atoms per molecule. and Examiner's Use Alkenes are more reactive than alkanes and are used to make a range of organic chemicals. Propene, CH3–CH=CH2, is made by cracking. Give the structural formula of the addition product when propene reacts with the following. water bromine Propene reacts with hydrogen iodide to form 2 - iodopropane. CH3−CH=CH2 + HI CH3−CHI−CH3 1.4 g of propene produced 4.0 g of 2 - iodopropane. Calculate the percentage yield. moles of CH3–CH=CH2 reacted = maximum moles of CH3–CHI–CH3 that could be formed = mass of one mole of CH3–CHI–CH3 = 170 g maximum mass of 2 - iodopropane that could be formed = percentage yield %
11. Organic chemistry  →  11.5. Alkenes
11. Organic chemistry  →  11.4. Alkanes
11. Organic chemistry  →  11.3. Fuels
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