0620_w12_qp_22 - revisedeck

0620_w12_qp_22

A paper of Chemistry, 0620

Questions:

7

Year:

2012

Paper:

2

Variant:

2

Login to start this paper & get access to powerful tools

1

For Examiner’s Use The diagram shows the structures of ﬁ ve elements, A, B, C, D and E. C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C Cu Cu Cu Cu Cu Cu Cu Cu Cu Cu Cu Cu A B C D E Cl Cl Cl Cl Cl Cl P P P P P P P P P P P P He He He He He He Answer these questions using the letters A, B, C, D or E. Each element can be used once, more than once or not at all. Which one of these elements is in Group V of the Periodic Table, is used to ﬁ ll weather balloons, is a diatomic gas at room temperature, conducts electricity, is a transition element? Which two of the elements A, B, C, D or E are simple molecules? and Which two of the words or phrases in the list below describe the structure of element B? covalent giant ionic metallic simple atomic simple molecular and What do you understand by the term element ?

2. Atoms, elements and compounds → 2.2. Atomic structure and the Periodic Table

8. The Periodic Table → 8.1. Arrangement of elements

Open

2

For Examiner’s Use Ammonia, NH3, is an alkaline gas. Describe a test for ammonia. test result What is the pH of an aqueous solution of ammonia? Put a ring around the correct answer. pH 1 pH 3 pH 5 pH 7 pH 9 Ammonia reacts with hydrochloric acid. Complete the symbol equation for this reaction. NH3 + HCl → Hydrochloric acid can be made by dissolving hydrogen chloride, HCl, in water. Draw a diagram to show the arrangement of electrons in hydrogen chloride. Show only the outer electrons. Show a hydrogen electron as ● Show a chlorine electron as x For Examiner’s Use Aqueous ammonia reacts with sulfuric acid to form a solution of ammonium sulfate. 2NH3+ H2SO4 → (NH4)2SO4 Ammonium sulfate is a colourless salt. Describe how you could use a titration method to make a colourless solution of ammonium sulfate. How can crystals of ammonium sulfate be obtained from a solution of ammonium sulfate?

12. Experimental techniques and chemical analysis → 12.5. Identification of ions and gases

6. Chemical reactions → 6.3. Reversible reactions and equilibrium

Open

3

For Examiner’s Use The table below shows the properties of some halogens. halogen colour state at room temperature melting point / °C ﬂ uorine yellow –220 chlorine light green gas bromine brownish-red liquid –7 iodine grey-black solid +114 What is the trend in the colour of the halogens down the Group? Predict the state of ﬂ uorine at room temperature. Predict the melting point of chlorine. The reactivity of three different halogens was compared by reacting them with solutions of sodium halides. The results are shown in the table below. reaction mixture observations astatine + sodium iodide colour of reaction mixture remains unchanged bromine + sodium iodide mixture turns dark brown chlorine + sodium bromide mixture turns brownish-red Use the results in the table to suggest the order of reactivity of astatine, bromine, chlorine and iodine. most reactive least reactive Predict whether bromine will react with sodium chloride solution. Explain your answer. For Examiner’s Use Chlorine reacts with excess cold dilute sodium hydroxide. The products of the reaction are sodium chloride, sodium chlorate(and water. The formula of sodium chlorate(is NaCl O. Complete the equation for this reaction. Cl 2 + NaOH → NaCl + NaCl O + Explain why chlorine is used in water puriﬁ cation. Impure water contains particles of minerals and remains of dead plants and animals. One stage in water puriﬁ cation is the removal of these particles by ﬁ ltration. The diagram below shows a water ﬁ lter. water in small particles of sand Explain how this water ﬁ lter works.

8. The Periodic Table → 8.3. Group VII properties

12. Experimental techniques and chemical analysis → 12.5. Identification of ions and gases

Open

4

For Examiner’s Use The process of distillation is used in an oil reﬁ nery to separate petroleum into different fractions. What do you understand by the term petroleum fraction ? Some petroleum fractions are more useful than others. There is a greater demand for these fractions. The diagram shows the demand from customers and the ability of an oil reﬁ nery to supply these fractions by fractional distillation alone. percentage refinery gas gasoline kerosene diesel fuel oil lubricating oil and bitumen supply from refinery demand State the name of two fractions for which demand is greater than supply. State one use for each of the following fractions. reﬁ nery gas bitumen More gasoline can be made by cracking long-chain hydrocarbons. State the conditions needed for cracking. For Examiner’s Use Dodecane, C12H26, can be cracked to form smaller hydrocarbons. What do you understand by the term hydrocarbon ? Complete the equation for the cracking of dodecane. C12H26 → C8H18 + Ethene, C2H4, can be formed by cracking. Draw the full structure of ethene showing all atoms and bonds. Polycan be made from ethene. Complete the following sentences using words from the list below. addition atoms condensation dimers monomers polymers subtraction The small ethene molecules which join together to form polyare called ethene . The process of joining the ethene molecules together is an example of an reaction. The long-chain molecules which are formed are called .

11. Organic chemistry → 11.3. Fuels

Open

5

For Examiner’s Use Aluminium is in Group III of the Periodic Table. Iron is a transition element. Both aluminium and iron have high melting points and boiling points. State two differences in the physical properties of aluminium and iron. State one use of aluminium. Sodium hydroxide is used to test for aluminium ions. Describe what happens when you add a solution of sodium hydroxide to a solution of aluminium ions until the sodium hydroxide is in excess.

9. Metals → 9.6. Extraction of metals

12. Experimental techniques and chemical analysis → 12.5. Identification of ions and gases

9. Metals → 9.2. Uses of metals

Open

6

For Examiner’s Use The diagram below shows a kiln used for manufacturing lime. air blown in waste gases mixture of calcium carbonate and coke lime removed The reaction taking place in the kiln is calcium carbonate → calcium oxide + carbon dioxide State the name of a rock which is largely calcium carbonate. Explain why, at the end of the reaction, there is only lime left in the lime kiln. Coke is mainly carbon. Combustion of coke provides the heat for the reaction in the lime kiln. Write a symbol equation for the complete combustion of carbon in oxygen. Complete these sentences using words from the list below. air dioxide harmless hydrogenated limited monoxide poisonous water When carbon burns in a supply of , carbon is formed. This is a colourless gas which has no smell and is . For Examiner’s Use Calcium carbonate reacts with hydrochloric acid to form carbon dioxide. Complete the word equation for this reaction. calcium carbonate carbon dioxide + + + → hydrochloric acid The speed of reaction of calcium carbonate with hydrochloric acid can be found using the apparatus shown below. cotton wool top pan balance hydrochloric acid small pieces of calcium carbonate Suggest how this apparatus can be used to ﬁ nd the speed of this reaction. State how the speed of this reaction changes when the concentration of acid is increased, larger pieces of calcium carbonate are used, the temperature is increased.

9. Metals → 9.4. Reactivity series

6. Chemical reactions → 6.2. Rate of reaction

9. Metals → 9.6. Extraction of metals

Open

7

For Examiner’s Use The structures of iodine and potassium iodide are shown below. I– K+ I– K+ I– I– K+ K+ I– K+ I– K+ I– I– K+ I I I I I I I I I I I I I I I I I I I I I I I I K+ iodine potassium iodide Iodine is a solid at room temperature. Its melting point is +114 °C. Describe what happens to the arrangement and movement of iodine molecules when iodine is gradually heated from 20 °C to 120 °C. Calculate the relative molecular mass of iodine. What type of bonding is present in potassium iodide? Write the simplest formula for potassium iodide. For Examiner’s Use Complete the table below to show the solubility in water and electrical conductivity of solid iodine and solid potassium iodide. substance solubility in water electrical conductivity of solid iodine potassium iodide Predict the product formed at each electrode when molten potassium iodide is electrolysed. at the positive electrode at the negative electrode

2. Atoms, elements and compounds → 2.4. Ions and ionic bonds

2. Atoms, elements and compounds → 2.5. Simple molecules and covalent bonds

Open