0620_s09_qp_2
A paper of Chemistry, 0620
Questions:
7
Year:
2009
Paper:
2
Variant:
0
Login to start this paper & get access to powerful tools
1
For Examiner's Use Choose from the list of compounds to answer questions to . calcium carbonate carbon dioxide hydrogen chloride iron(oxide lead(bromide methane sodium hydroxide Each compound can be used once, more than once or not at all. Name the compound which is a transition metal compound, produces brown fumes at the anode when electrolysed, is used to manufacture lime, dissolves in water to form an alkaline solution, is the main constituent of natural gas. For Examiner's Use At a high temperature iron(oxide is reduced by carbon. Fe2O3 + 3C 2Fe + 3CO Explain how the equation shows that iron(oxide is reduced by carbon. Complete these sentences about the extraction of iron using words from the list. bauxite blast converter haematite lime limestone sand slag Iron is extracted from by mixing the ore with coke and in a furnace. The iron ore is reduced to iron and impurities in the ore react with calcium oxide to form .
9. Metals  →  9.6. Extraction of metals
Open
2
For Examiner's Use The table shows some observations about the reactivity of various metals with dilute hydrochloric acid. metal observations calcium many bubbles produced rapidly with much spitting copper no bubbles formed iron a few bubbles produced very slowly magnesium many bubbles produced rapidly with no spitting Put these metals in order of their reactivity. most reactive least reactive Zinc is between iron and magnesium in its reactivity. Suggest what observations are made about how fast the bubbles are produced when zinc reacts with dilute hydrochloric acid. Magnesium is extracted by the electrolysis of molten magnesium chloride. inert gas molten magnesium molten magnesium chloride iron cathode (–) anode (+) What information in the diagram suggests that magnesium is less dense than molten magnesium chloride? For Examiner's Use Suggest why magnesium has to be extracted by electrolysis rather than by heating its oxide with carbon. Suggest why a stream of inert gas is blown over the surface of the molten magnesium. State the name of a gaseous element which is inert. In some old magnesium manufacturing plants, coal gas is blown over the surface of the magnesium. The list shows the main substances in coal gas. carbon monoxide ethene hydrogen hydrogen sulfide methane Draw the structure of ethene showing all atoms and bonds. Suggest two hazards of using coal gas by referring to two specific substances in the list. substance hazard substance hazard For Examiner's Use Carbon monoxide can be removed from coal gas by mixing it with steam and passing the mixture over a catalyst of iron(oxide at 400 ºC. CO + H2O CO2 + H2 Write a word equation for this reaction. What does the symbol mean? Iron(oxide reacts with acids to form a solution containing iron(ions. Describe a test for aqueous iron(ions. test result
9. Metals  →  9.4. Reactivity series
9. Metals  →  9.6. Extraction of metals
Open
3
For Examiner's Use Petroleum is a mixture of hydrocarbons which can be separated into fractions such as petrol, paraffin and diesel. State the name of the process used to separate these fractions. Name two other fractions which are obtained from petroleum . and Give one use for the paraffin fraction. Many of the compounds obtained from petroleum are alkanes. Which two of the following structures are alkanes? C A B H H H H C C H H O H H C D H H C H C H H H H H C C H H H H Use words from the list below to complete the following sentence. ethane ethene hydrogen nitrogen oxygen reactive unreactive water Alkanes such as are generally but they can be burnt in to form carbon dioxide and Alkanes are saturated hydrocarbons. What do you understand by the terms saturated, hydrocarbon?
11. Organic chemistry  →  11.4. Alkanes
11. Organic chemistry  →  11.3. Fuels
Open
4
For Examiner's Use This question is about some compounds of nitrogen. A mixture of ammonium sulfate and sodium hydroxide was warmed in a test-tube. The gas was tested with moist red litmus paper. heat gently red litmus paper ammonium sulfate and sodium hydroxide State the name of the gas released. State the colour change of the litmus paper. Complete the word equation for the reaction of ammonium carbonate with hydrochloric acid. ammonium + hydrochloric ……… + ……… + ……… carbonate acid ……… ……… Ammonium salts such as ammonium nitrate, NH4NO3 and ammonium chloride NH4Cl are used as fertilisers. Explain why farmers need to use fertilisers. Explain why ammonium nitrate is a better fertiliser than ammonium chloride. For Examiner's Use Calculate the relative formula mass of ammonium nitrate. When ammonium nitrate is heated nitrogen(oxide is given off. Nitrogen(oxide relights a glowing splint. Name one other gas which relights a glowing splint. State one harmful effect of nitrogen oxides on the environment.
10. Chemistry of the environment  →  10.2. Fertilisers
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
Open
5
For Examiner's Use 100.4 100.3 100.2 100.1 100.0 mass of flask and contents / grams time / seconds A student used the apparatus shown below to investigate the rate of reaction of calcium carbonate with dilute hydrochloric acid. CaCO3 + 2HCl CaCl2 + CO2 + H2O cotton wool dilute hydrochloric acid calcium carbonate balance 100.4 Use the information in the equation to suggest why the mass of the flask and contents decreases with time. The graph shows how the mass of the flask and its contents changes with time. For Examiner's Use At what time was the reaction just complete? On the graph, mark with an X the point where the speed of reaction was fastest. The student repeated the experiment but altered the concentration of the hydrochloric acid so that it was half the original value. In both experiments calcium carbonate was in excess and all other conditions were kept the same. On the graph on page 10, draw a curve to show how the mass of the flask and contents changes with time when hydrochloric acid of half the concentration was used. How does the speed of this reaction change when the temperature is increased, smaller pieces of calcium carbonate are used? Complete the following sentence using words from the list. combustion expansion large rapid slow small In flour mills there is often the risk of an explosion due to the rapid of the very particles which have a very surface area to react. Cells in plants and animals break down glucose to carbon dioxide and water. glucose + oxygen carbon dioxide + water State the name of this process. In this process enzymes act as catalysts. What do you understand by the term catalyst?
6. Chemical reactions  →  6.2. Rate of reaction
Open
6
For Examiner's Use Bromine is an element in Group VII of the Periodic Table. Write the formula for a molecule of bromine. Complete the diagram below to show the arrangement of the molecules in liquid bromine. represents a bromine molecule A teacher placed a small amount of liquid bromine in the bottom of a sealed gas jar of air. After two minutes brown fumes were seen just above the liquid surface. After one hour the brown colour had spread completely throughout the gas jar. start after 2 minutes after liquid bromine air Use the kinetic particle theory to explain these observations. For Examiner's Use Magnesium salts are colourless but Group VII elements are coloured. An aqueous solution of magnesium bromide reacts with an aqueous solution of chlorine. magnesium bromide + chlorine magnesium chloride + bromine State the colour change in this reaction. A solution of magnesium bromide will not react with iodine. Explain why there is no reaction. The structures of some compounds containing bromine are shown below. Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Zn2+ Br – Br – Zn2+ Br – Br – Zn2+ Br – Br – Zn2+ Br – Br – A B C D H Br Br F F F Write the simplest formula for the substance with structure A. State the name of the substance with structure D. State the type of bonding within a molecule of structure C. Which two structures are giant structures? and Why does structure A conduct electricity when it is molten?
8. The Periodic Table  →  8.3. Group VII properties
11. Organic chemistry  →  11.5. Alkenes
Open
7
For Examiner's Use Hydrogen chloride can be made by burning hydrogen in chlorine. Complete the equation for this reaction. H2 + ………… ……… HCl Draw a dot and cross diagram for a molecule of hydrogen chloride. Show all the electrons. use o for an electron from a hydrogen atom use x for an electron from a chlorine atom Hydrochloric acid is formed when hydrogen chloride gas dissolves in water. Suggest the pH of hydrochloric acid. Put a ring around the correct answer. pH 1 pH7 pH9 pH 13 Complete the equation for the reaction of hydrochloric acid with zinc. zinc + hydrochloric acid zinc chloride + ……………… Describe how dry crystals of zinc chloride can be obtained from a solution of zinc chloride. A student electrolysed molten zinc chloride. State the name of the product formed at the anode, the cathode.
4. Electrochemistry  →  4.1. Electrolysis
9. Metals  →  9.4. Reactivity series
Open