Chemistry Paper 2

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INFORMATION FOR CANDIDATES MAKLUMAT UNTUK CALON 1. This question paper consists of three sections: Sections A, B and C. Kertas soalan ini mengandungi tiga bahagian: Bahagian A, B dan C. 2. Answer all questions in Section A. Write your answers for Section A in the spaces provided in the question paper. Jawab semua soalan dalam Bahagian A. Tuliskan jawapan bagi Bahagian A dalam ruang yang disediakan dalam kertas soalan 3. Answer one question from Section B and one question from Section C. Write your answers for Section B and Section C on the `writing paper’ provided by the invigilators. Answer questions in Section B and Section C in detail. You may use equations, diagrams, tables, graphs and other suitable methods to explain your answer. Jawab satu soalan daripada Bahagian B dan satu soalan daripada Bahagian C. Tuliskan jawapan bagi Bahagian B dan Bahagian C pada halaman bergaris di bahagian akhir kertas soalan ini. Jawab Bahagian B dan Bahagian C dengan terperinci. Anda boleh menggunakan persamaan, gambar rajah, jadual, graf dan cara lain yang sesuai untuk menjelaskan jawapan anda 4. Show your working. It may help you to get marks. Tunjukkan kerja mengira.Ini membantu anda mendapatkan markah. 5. If you wish to change your answer, neatly cross out the answer that you have done. Then write down the new answer. Sekiranya anda hendak membatalkan sesuatu jawapan, buat garisan di atas jawapan itu. 6. The diagrams in the questions are not drawn to scale unless stated. Rajah yang mengiringi soalan tidak dilukiskan mengikut skala kecuali dinyatakan 7. Marks allocated for each question or part question are shown in brackets. Markah yang diperuntukkan bagi setiap soalan atau ceraian soalan ditunjukkan dalam kurungan 8.

The time suggested to answer Section A is 90 minutes, Section B is 30 minutes and Section C is 30 minutes. Masa yang dicadangkan untuk menjawab Bahagian A ialah 90 minit, Bahagian B ialah 30 minit dan Bahagian C ialah 30 minit

9. You may use a non-programmable scientific calculator. Anda dibenarkan menggunakan kalkulator saintifik yang tidak boleh diprogramkan. 10. Hand in your answer sheets at the end of the examination. Serahkan semua kertas jawapan anda di akhir peperiksaan

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Section A [60 marks] Answer all questions Jawab semua soalan 1 Table 1 shows the proton number and nucleon number for atoms P, Q and R. Jadual 1 menunjukkan nombor proton dan nombor nukleon bagi atom P, Q dan R.

(a) (i)

Atom

Proton number

Nucleon number

P

16

32

Q

17

35

R

17 Table 1

37

What is meant by proton number? Apakah yang dimaksudkan dengan nombor proton ? ...............................................................................……………................… [1 mark]

(ii)

What is the number of neutrons in atom Q ? Apakah bilangan neutron dalam atom Q? ................ ................................................................................. ………………………… ....................................................................................................................... [1 mark]

(b) Which atoms are isotopes? Explain your answer. Atom- atom yang manakah adalah isotop? Terangkan jawapan anda. ................................................................................................................................. .................................................................................................…………………… [2 marks] (c) (i)

Write the electron arrangement for atom R. Tuliskan susunan elektron bagi atom R. ....................................................................................................................... [1 mark]

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(ii)

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Draw the electron arrangement of atom R. Lukiskan susunan elektron bagi atom R.

[2 marks] (iii)

State the number of valence electrons for atom R. Nyatakan bilangan elektron valens bagi atom R. ....................................................................................................................... [1 mark]

(iv)

Write the formula of ion formed from atom R. Tuliskan formula ion yang terbentuk daripada atom R. ....................................................................................................................... [1 mark]

(v)

State how the ion in (c)(iv) is formed. Nyatakan bagaimana ion dalam (c)(iv) terbentuk. ....................................................................................................................... [1 mark]

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2 Diagram 2 shows the set-up of apparatus for an electrolytic cell. Rajah 2 menunjukkan susunan radas untuk satu sel elektrolisis.

Copper(II) nitrate solution Diagram 2 (a) State the energy change in the cell . Nyatakan perubahan tenaga dalam sel itu. …………………………………………………………………………………….. [1 mark] (b )

Label the anode in the cell. Labelkan anod dalam sel itu. [1 mark]

(c) State one observation at the anode. Nyatakan satu pemerhatian pada anod. …………………………………………………………………………………….. [1 mark] (d )

Write the half equation for the reaction that takes place at the anode. Tuliskan setengah persamaan untuk tindak balas yang berlaku di anod. …………………………………………………………………………………….. [1 mark]

(e) State the factor that affects the selective discharge of ions at the cathode of the cell. Nyatakan faktor yang mempengaruhi discas secara pilihan ion di katod sel itu. …………………………………………………………………………………….. [1 mark]

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What happens to the colour intensity of the solution in the cell? Explain your answer. Apakah yang berlaku kepada keamatan warna larutan dalam sel itu? Terangkan jawapan anda. …………………………………………………………………………………….. …………………………………………………………………………………….. …………………………………………………………………………………….. [2 marks]

(g) (i)

One of the uses of electrolysis in industry is electroplating of metals. State another use of electrolysis in industry. Satu daripada kegunaan elektrolisis dalam industri ialah penyaduran logam. Nyatakan satu lagi kegunaan elektrolisis dalam industri. ……………………………………………………………………………… [1 mark]

(ii)

A student wants to electroplate an iron spoon with silver. Draw the apparatus set-up that will be used by the student. Seorang pelajar ingin menyadurkan sudu besi dengan argentum. Lukiskan susunan radas yang akan digunakan oleh pelajar tersebut.

[2 marks]

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3 Table 3 shows two alloys and their components. Alloy Bronze Pewter

Component 90% copper 5% element X 96% tin 3% copper 1% antimony Table 3

(a) Name element X. Namakan unsur X. ...……………………………………………………….…………………….......... [1 mark] (b )

What type of particle is found in pure copper? Apakah jenis zarah yang terdapat dalam kuprum tulen? …………………………………………………………….……………………… [1 mark]

(c) Draw the arrangement of particles in pure copper and in bronze. Lukiskan susunan zarah yang terdapat dalam kuprum tulen dan gangsa. (i)

Pure copper Kuprum tulen

[1 mark] (ii)

Bronze Gangsa

[2 marks]

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Explain why bronze is harder than pure copper. Terangkan mengapa gangsa lebih keras daripada kuprum tulen. ………………………………………………………………..……………........... ………………………………………………………………..……………........... ………………………………………………………………..……………........... ………………………………………………………………..……………........... [3 marks]

(e) State two aims of alloying other than hardness. Nyatakan dua tujuan pengaloian selain daripada kekerasan. ..………………………………………………………..……………..................... [2 marks]

4

An experiment is carried out to determine the rate of reaction between excess calcium carbonate and 50.0 cm3 of 0.2 mol dm-3 hydrochloric acid. The volume of carbon dioxide gas produced is recorded at 30 seconds intervals. The result obtained is recorded in Table 4. Satu eksperimen telah dijalankan untuk menentukan kadar tindak balas antara 50.0 cm3 asid hidroklorik 0.2 mol dm-3 dengan kalsium karbonat berlebihan. Isipadi gas karbon dioksida yang terbebas direkodkan pada setiap 30 saat dalam Jadual 4. Time/s Volume/cm3

0 0

30 17

60 90 29 34 Table 4

120 36

150 36

180 36

210 36

240 36

(a) Based on Table 4, draw a graph of volume of carbon dioxide gas against time. Berdasarkan Jadual 4, lukis graf isipadu gas karbon dioksida melawan masa. [4 marks] (b) Calculate the average rate of reaction for this experiment. Hitungkan kadar tindak balas purata bagi tindak balas ini. [2 marks]

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(c) If the experiment is repeated by using 50.0 cm3 of 0.1 mol dm-3 hydrochloric acid, sketch the expected curve in graph (b) . Jika eksperimen diulangi menggunakan 50.0 cm3 asid hidroklorik 0.1 mol dm-3, lakarkan lengkung yang dijangkakan dalam graf (b). [2 marks] (d) The factor that affects the rate of reaction in this experiment is concentration. State two other factors that can affect the rate of reaction in this experiment. Faktor yang mempengaruhi kadar tindak balas dalam eksperimen ini ialah kepekatan. Nyatakan dua lagi faktor yang dapat mempengaruhi kadar tindak balas eksperimen ini. …………………………………………………………………………………. …………………………………………………………………………………. [2 marks]

5

Figure 5 shows the set up of the apparatus for an experiment to investigate electron transfer at a distance. Rajah 5 menunjukkan susunan radas bagi satu eksperimen untuk mengkaji pemindahan elektron pada satu jarak.

G

Electrode P

Electrode Q Bromine water

Iron (II) sulphate solution

Sulphuric acid

Figure 5 Based on Figure 5, answer the following questions. Berdasarkan Rajah 5, jawab soalan-soalan berikut. (a)

Draw the flow of electron in Figure 5. Lukiskan arah aliran elektron dalam Rajah 5. [1 mark]

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State the function of sulphuric acid. Nyatakan fungsi asid sulfurik. …………………………………………………………………………………… [1 mark]

(c)

State the observations for iron(II) sulphate solution and bromine water. Nyatakan pemerhatian untuk larutan ferum(II) sulfat dan air bromin. Solution Larutan

Observation Pemerhatian

Iron(II) sulphate Bromine water [2 marks] (d)

Write the half equation for the reactions that occur at electrode P and Q. Tuliskan setengah persamaan bagi tindak balas yang berlaku pada elektrod P dan Q (i) Electrode P : ……………………………………………………………….. (ii) Electrode Q : ………………………………………………………….……. [2 marks]

(e)

State the oxidising agent and the reducing agent. Nyatakan agen pengoksidaan dan agen penurunan. (i) Oxidising agent : Agen pengoksidaan: ………………………………………………………… (ii) Reducing agent: Agen penurunan…………………………………………………………………… [2 marks]

(f)

State the change of oxidation number for iron in iron(II) sulphate solution. Nyatakan perubahan nombor pengoksidaan bagi ferum dalam larutan ferum(II) sulfat. …………………………………………………………………………………… [1 mark]

(g)

Name one chemical substance that can be used to replace bromine water. Namakan satu bahan kimia yang boleh digunakan untuk menggantikan air bromin. …………………………………………………………………………………… [1 mark]

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6 Structure A and B represent molecules of two common cleaning agents, soap and detergent. Struktur A dan B mewakili molekul bagi dua bahan pencuci, sabun dan detergen. Structure A

Structure B

(a) Name the cleaning agent for Namakan bahan pencuci bagi Structure A :……………………………………………………………………… Structure B:……………………………………………………………………… [2 marks] (b) Soap is prepared by heating a mixture of a strong alkali solution and palm oil. Sabun disediakan dengan memanaskan satu campuran larutan alkali kuat dan minyak kelapa sawit. (i) Name the reaction for preparation of soap. Namakan tindak balas bagi penyediaan sabun. ………………………………………………………………………………….. [1 mark] (ii) Name one strong alkali used in preparing soap Namakan satu alkali kuat yang digunakan dalam penyediaan sabun. ………………………………………………………………………………….. [1 mark] (iii) Name the homologous series to which palm oil belongs to. Namakan siri homolog bagi kelapa sawit. ………………………………………………………………………………….. [1 mark]

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(c) The statement below is about soap and detergent. “The cleansing action of a detergent is more effective than soap in hard water” Explain the above statement. Kenyataan berikut adalah berkenaan sabun dan detergen. “Tindakan pencucian detergen lebih efektif daripada sabun dalam air liat.” Terangkan kenyataan di atas. ………………..………………………………………………………….………... …………………………………………………………………………………….. [2 marks] (d) Table 6 shows the functions of three types of medicine. Jadual 6 menunjukkan fungsi tiga jenis ubat. Function Fungsi

Type of medicine Jenis ubat

Relieve pain Mengurangkan kesakitan Kills or prevent the reproduction of bacteria Membunuh atau penghalang pertumbuhan bakteria Changes the emotions and behaviour of the patient Mengubah emosi dan perlakuan pesakit Table 6 Complete Table 6 by writing the type of medicine in the spaces provided. Lengkapkan jadual 6 dengan menulis jenis ubat di ruang yang disediakan. [3 marks]

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Section B [ 20 marks ] Answer any one question. Jawab mana-mana satu soalan. 7

Figure 7 shows one of the element in the Periodic Table of Elements. Rajah 7 menunjukkan satu daripada unsur di dalam Jadual Berkala Unsur.

24 12 X Figure 7 (a)

Explain how to determine the position of element X in the Periodic Table of Elements. Terangkan bagaimana menentukan kedudukan unsur X dalam Jadual Berkala Unsur. [5 marks]

(b)

Proton number of lithium and sodium are 3 and 11 respectively. Explain why lithium is less reactive than sodium. Nombor proton litium dan natrium ialah 3 dan 11 masing-masing. Terangkan mengapa litium kurang reaktif daripada natrium. [5 marks]

(c)

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Describe an experiment to compare the reactivity of lithium and sodium when reacted with water. Your description should also include the observations, the name of products and chemical equations for the reactions. Huraikan satu eksperimen untuk membandingkan kereaktifan litium dan natrium apabila bertindak balas dengan air. Huraian anda perlu juga mengandungi pemerhatian, nama hasil tindak balas dan persamaan kimia bagi tindak balas yang berlaku. [10 marks]

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Diagram 8 shows information about a hydrocarbon P. Rajah 8 menunjukkan maklumat berkenaan hidrokarbon P.    

Carbon Hydrogen Relative molecular mass Relative atomic mass

: 85.7% : 14.3 % : 42 : C=12 ; H=1

Diagram 8 (a) Based on the information given, Berdasarkan maklumat yang diberikan, o determine the molecular formula of P. tentukan formula molekul bagi P. o draw the structural formula of P. lukiskan formula struktur P. o name P. namakan P. o write the general formula of P. tuliskan formula am bagi P., [10 marks] (b) Hydrocarbon P can be converted into hydrocarbon Q by hydrogenation reaction. Hidrokarbon P boleh ditukarkan kepada hidrokarbon Q melalui tindak balas penghidrogenan. (i) Write a chemical reaction for this reaction. Tuliskan persamaan kimia bagi tindak balas ini. [1 mark] (ii) Hydrocarbon P and Q are burnt completely in air. Compare the sootiness of the flame produced during the reaction. Explain your answer. Hidrokarbon P dan Q terbakar dengan lengkap dalam udara. Bandingkan kejelagaan nyalaan yang terhasil semasa tindak balas ini. Terangkan jawapan anda. [6 marks]

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Figure 9 shows the symbols which represent three elements W, X and Y. Rajah 9 menunjukkan yang mewakili tiga unsur W, X dan Y. (c) Describe briefly how tosimbol convert P into an alcohol. Huraikan secara ringkas bagaimana P boleh ditukarkan kepada satu alkohol.

.

12 W 6

7 X 3

35 Y 17

[3 marks]

Figure 9 (a) Elements W and Y react to form a covalent compound, while elements X and Y react to form an ionic compound. Unsur W dan unsur Y bertindak balas untuk membentuk sebatian kovalen, manakala unsur X dan unsur Y bertindak balas untuk membentuk sebatian ionik. Describe the formation of the chemical compounds between Huraikan pembentukan sebatian kimia antara (i)

elements W and Y

(ii)

elements X and Y [16 marks]

(b )

`Ionic compound has higher melting point than covalent compound` ` Sebatian ion mempunyai takat lebur yang lebih tinggi daripada sebatian kovalen`

Explain the above statement. Terangkan pernyataan di atas. [4 marks]

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10 The thermochemical equation for the combustion of butanol is given as follows: Persamaan termokimia bagi pembakaran butanol adalah seperti berikut. C4H9OH + 6O2 

4CO2 + 5H2O

∆H = -2679 kJmol-1

[Relative atomic mass : H=1, C=12, O=16, specific heat capacity of water = 4.2 Jg-1 oC-1] (a) Write three interpretations or statements that can be obtained from the above equation. Tuliskan tiga interpretasi atau kenyataan yang boleh dibuat dari persamaan di atas. [3 marks] (b) Calculate the mass of butanol that must be burnt to raise the temperature of 400 cm3 of water by 25°C. Kira jisim butanol yang perlu dibakar untuk menaikkan suhu 400 cm3 air sebanyak 25°C. [3 marks] (c) Describe an experiment to determine the heat of combustion of butanol. Your answer should include: Huraikan satu eksperimen untuk menentukan haba pembakaran butanol. Jawapan anda mestilah mengandungi: (i)

apparatus set-up susunan radas yang digunakan [2 marks]

(ii)

procedure of the experiment prosedur eksperimen [6 marks]

(iii) data obtained from the experiment data yang diperolehi daripada eksperimen [2 marks] (iv) calculation of heat of combustion of butanol. penghitungan haba pembakaran butanol. [4 marks]

END OF QUESTION PAPER

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SPACE FOR ANSWER Section…………………. Question No………………………….. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 4541/2

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Section…………………. Question No………………………….. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 4541/2

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Section…………………. Question No………………………….. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________

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