Chemistry

1. 1 Diagram 1 shows an experiment to determine the empirical formula of copper (II) oxide.
Result :
Mass of combustion tube + asbestos paper = 58.36 g
Mass of combustion tube + asbestos paper + copper (II) oxide = 91.96 g
Mass of combustion tube + asbestos paper + copper = 85.24 g
(a) What is meant by empirical formula?
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[1 mark]
(b) What is the function of anhydrous calcium chloride?
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[1 mark]
(c) How to ensure that the combustion tube has been totally filled with hydrogen gas?
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[2 marks]
(d) Based on the above results,
(i) Calculate the mass of copper and the mass of oxygen that have reacted.
[1 mark]
DIAGRAM / RAJAH 1
Zinc pieces
Ketulan zink
Copper(II) oxide
Kuprum(II) oksida
Heat
Panaskan
Dilute
hydrochloric acid
Asid hidroklorik
cair
Anhydrous calcium chloride
Kalsium klorida kontang
Hydrogen gas
Gas hidrogen
Asbestos paper
Kertas asbestos
Combustion tube
Tiub pembakaran Hydrogen flame
Nyalaan hidrogen

2. (ii) Calculate the mole ratio of copper atoms to oxygen atoms.
[ Relative atomic mass / Jisim atomrelatif :O = 16 ; Cu = 64 ]
[1 mark]
(iii) Determine the empirical formula of copper (II) oxide.
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[1 mark]
(iv) Write the chemical equation for the reaction in the experiment.
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[1 mark]
(e) Does this method suitable to determine the empirical formula of aluminium oxide?
Explain your answer.
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[2 marks]
2 Table 2 shows the proton number of a few elements in Period 3.
Element Sodium Magnesium Aluminium Chlorine Argon
Proton number 11 12 13 17 18
TABLE / JADUAL 2
Based on Table 2, answer the following questions :
(a) Name two metals.
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[1 mark]
(b) Chlorine is in the group 17 in the Periodic Table. What is another name for group 17?
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[1 mark]

3. (c) Write the electron arrangement of aluminium atom.
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[1 mark]
(d) (i) Arrange the element in Table 2 according to their atomic sizes in
descending order.
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[1 mark]
(ii) Explain your answer in (d) (i).
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[2 marks]
(e) When sodium is burnt in chlorine, sodium chloride is formed.
(i) State one observation.
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[1 mark]
(ii) Write the chemical equation for the reaction.
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[2 marks]
(iii) State one physical property of sodium chloride.
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[1 mark]
3 Diagram 3 shows the set-up of apparatus of a chemical cell.
(a) What is the function of the porous pot?
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[1 mark]
(b) What is the energy change that occurs in the cell?
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[1 mark]
Copper plate /
Kepingan kuprum
Zinc plate /
Kepingan zink
Copper(II) sulphate solution /
Larutan kuprum(II) sulfat
Zinc sulphate solution /
Larutan zink sulfat
Porous pot /
Pasu berliang
DIAGRAM / RAJAH 3

4. (c) State which metal plate acts as the
negative terminal :
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positive terminal :
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[1 mark]
(d) Write the half equation of the reaction at the
negative terminal :
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[1 mark]
positive terminal :
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[1 mark]
(e) What is the colour change of the copper (II) sulphate solution? Explain your answer.
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[2 marks]
(f) Draw arrows indicating the flow of electrons in Diagram 3.
[1 mark]
(g) Describe how to increase the cell voltage.
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[2 marks]
4 Table 4 shows four types of salts.
With reference to the salts given above, answer the following question :
(a) Write the chemical formula of sodium carbonate.
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[1 mark]
(b) Name the salt which is insoluble in water.
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[1 mark]
Sodium carbonate / Natriumkarbonat
Zinc nitrate / Zink nitrat
Lead(II) chloride / Plumbum(II) klorida
Copper(II) sulphate / Kuprum(II) sulfat
TABLE / JADUAL 4

5. (c) (i) What is observed when zinc nitrate salt is heated.
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[1 mark]
(ii) Write the chemical equation to represent the reaction.
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[2 marks]
(d) State the type of reaction in the preparation of lead(II) chloride salt.
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[1 mark]
(e) Describe how to verify copper(II) ion and sulphate ion in copper(II) sulphate solution.
Copper(II) ion : ...............................................................................................................
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Sulphate ion : ...............................................................................................................
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[4 marks]
5 Diagram 4 shows the steps involved in the industrial process in manufacturing ammonia
DIAGRAM 4
(a) Name this industrial process
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[ 1 mark]
(b) State the pressure and the catalyst used in the reaction.
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[ 2 marks]
(c) Write an equation for the reaction in the catalyst chamber.
`
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[ 2 marks]
(d) State one use of ammonia
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[ 2 marks]
Nitrogen
Hydrogen
Compressed
Catalyst
chamber
Ammonia

6. (e)
(i) What is the element added to iron in the making of steel.
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[ 1 mark]
(ii) Explain why steel is harder than pure metal.
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[ 3 marks]
6 The following is information about substance X.
In an experiment to determine the melting point of substance X , a boiling tube containing
solid X is heated using a water bath until its temperature is above its melting point.
(a) Draw and label a diagram of apparatus that is used in the experiment.
[ 2 marks]
(b) What is meant by melting point?
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[ 1 mark]
(c ) What is the purpose of using water bath in the experiment?
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[ 1 mark]
(d) Draw the arrangement of particles of substance X at 400
C and 900
C respectively.
[ 2 marks]
 Solid at room temperature
 Melting point is 80 0
C
 Highly flammable.
40 0 C 90 0 C
Steel consists of iron and other elements.
It is harder than pure metal

7. (e) Sketch a graph of temperature against time during the heating. Mark on the graph to
indicate the melting point of substance X.
[ 3 marks]
(f) Suggest the name of substance X.
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[ 1 mark]
7 Diagram 2.1 shows the set-up of the apparatus for an experiment to construct the
Electrochemical Series through the ability of metals to displace other metals from their salt
solution.
The experiment was repeated using metals silver, copper and P to replace zinc and P nitrate
solution to replace silver nitrate solution.
Diagram shows the result obtained.
Experiment Metal Silver nitrate solution P nitrate solution
I Zinc Silver metal is displaced. P metal is displaced.
II Copper Silver metal is displaced. No reaction.
III P Silver metal is displaced.
TABLE
(e) What is meant by Electrochemical Series?
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[1 mark]
Silver nitrate solution
Larutan argentum nitrat
Zinc plate
Kepingan zink
DIAGRAM

8. (b) Based on the results in Table 2.2, arrange the metals silver, copper, P and zinc in
ascending order of electropositivity.
[1 mark]
(c) Name the suitable metal P.
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[1 mark]
(d) Based on Experiment I :
(i) Zinc can displace silver metal from silver nitrate solution. Explain why.
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[1 mark]
(ii) Write the chemical equation for the reaction.
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[1 mark]
(iii) What is the change in the oxidation number of zinc?
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[1 mark]
(e) Diagram below shows the set up of apparatus for the reaction between metal P and
copper(II) nitrate solution.
What is the colour change of the of copper(II) nitrate solution?. Explain why.
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[2 marks]
(f) State two uses of the Electrochemical Series besides the determining the ability of a
metal to displace another metal from its salt solution.
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[2 marks]
More electropositive
Copper(II) nitrate solution
Larutan kuprum(II) nitrat
Metal P plate
Kepingan logamP