1. Steel is an alloy.Besi ialah aloi.

(a) Define alloy.Definisikan aloi.

[2 marks][2 markah]

(b) (i) Alloying a metal can increase its hardness. From the aspect of arrangement of atoms, explain why an alloy is harder than its pure metal.Pengaloian logam boleh meningkatkan kekuatan logam.Daripada segi susunan atom, terangkan mengapa aloi lebih kuat berbanding logam tulen.

[3 marks][3 markah]

(ii) Give one other reason for alloying a metal other than increasing hardness.Berikan satu sebab lain bagi pengaloian logam selain daripada meningkatkan

kekuatan logam.

[1 marks][1 markah]

(c) 50 cm3 of 5 mol dm-3 sodium hydroxide solution was added to 10 cm3 of oil palm. The mixture was heated for about 20 minutes. Then about 50 cm3 of water was added followed by two spatulas of sodium chloride. The mixture was stirred and then allowed to cool. Soap was formed.50 cm3 5 mol dm-3 larutan natrium hidroksida ditambah kepada 10 cm3 minyak kelapa sawit. Campuran dipanaskan selama 20 minit. Kemudian 50 cm3 air ditambah diikuti oleh dua spatula natrium klorida. Campuran dikacau dan kemudian dibiarkan sejuk. Sabun terbentuk.

(i) Name the reaction taking place when the mixture of oil palm and sodium hydroxide was heated.Namakan tindak balas yang berlaku apabila campuran minyak kelapa sawit dan natrium hidroksida dipanaskan.

[1 mark][1 markah]

(ii) Name another product formed in the reaction beside soap.Namakan hasil tindak balas lain yang terbentuk dalam tindak balas inu selain daripada sabun.

[1 mark][1 markah]

(iii What is the aim of adding sodium chloride during the reaction?Apakah tujuan menambah natrium klorida semasa tindak balas?

[1 mark][1 markah]

(iv)

Name another substance that can be used to replace oil palm.Namakan bahan lain yang boleh digunakan untuk menggantikan minyak kelapa sawit.

[1 mark][1 markah]

4. The graph below shows the temperature of a substance M as it is heated until it boils.Jadual di bawah menunjukkan suhu suatu bahan apabila ia dipanaskan sehingga mendidih.

(a) State the physical state of M at the regionNyatakan keadaan fizik M pada kawasan

(i) QR

(ii)ST

(iii) TU

[3 marks][3 markah]

(c) What is M's melting temperature?Apakah takat lebur M?

[1 mark][1 markah]

(d) Explain why the temperature remains constant during the period t1 to t2 although the heating process is still in progress?Jelaskan mengapa suhu kekal malar dalam tempoh masa t1 kepada t2 walaupun proses pemanasan masih lagi berjalan?

[1 mark][1 markah]

5. The table belwo shows the proton number and nucleon number of five particles V, W, X, Y and Z.Jadual di bawah menunjukkan nombor proton dan nombor nukleon bagi lima zarah V, W, X, Y dan Z.

ParticleZarah

Proton numberNombor proton

Nucleon number Nombor nukleon

Electron arrangement Susunan electron

VWXYZ

61181115

1223162431

(a) Write the electron arrangement for particle particle Y.Tuliskan susunan elektron bagi zarah zarah Y.

[1 mark][1 markah]

(b) What is the number of valence electrons of particle V?Berapakah bilangan elektron valens zarah V?

[1 mark][1 markah]

(g) (i) Explain the meaning of the term “isotope”.Jelaskan maksud sebutan “isotop”.

[2 marks][2 markah]

(ii) From the table above, pick a pair of isotopes.Daripada jadual di atas, pilih satu pasang isotop.

[1 mark][1 markah]

6. The figure below shows a portion of the Periodic Table. The letters listed below are not the actual symbols of the elements.Rajah di bawah menunjukkan sebahagian daripada Jadual Berkala. Huruf yang disenaraikan di bawah bukan simbol yang sebenar bagi unsur-unsur.

(c) Pick an element that forms a coloured compound.

Pilih satu unsur yang membentuk sebatian berwarna.

[1 mark][1 markah]

(d) Pick an element that exists as a monoatomic. Explain your answer.Pilih satu unsur yang wujud sebagai monoatom.Jelaskan jawapan anda.

[2 marks][2 markah]

(h) (i) Between the elements of E and R, which is more reactive? Explain your answer.Antara unsur E dan R, yang manakah lebih reaktif?Jelaskan jawapan anda.

[2 marks][2 markah]

7. Below is a list of elements represented by the symbols as shown:Berikut ialah senarai unsur yang diwakili oleh simbol-simbol yang ditunjukkan:

11 P, 12

6 Q, 199 R, 27

13 S, 3517 T, 39

19 U

(e) (i) Which element reacts with cold water?Unsur yang manakah bertindak balas dengan air sejuk?

[1 mark][1 markah]

(ii) Write a balanced chemical equation for the reaction.Tuliskan persamaan kimia yang seimbang bagi tindak balas tersebut.

[1 mark][1 markah]

(g)

(ii) Which of the two elements R and T is more electronegative? Explain your

answer.Antara dua unsur R dan T yang manakah lebih elektronegatif?Jelaskan jawapan anda.

[2 marks][2 markah]

8. The apparatus shown below is used to determine the empirical formula of oxide of metal M by reducing the metal oxide with dry hydrogen gas.(RAM O=16, M=55)Radas yang ditunjukkan di bawah digunakan untuk menentukan formula empirik bagi oksida logam M melalui penurunan logam oksida dengan gas hidrogen kering.(JAR O=16, M=55)

(a) State one precaution that must be taken when carrying out the experiment.Nyatakan satu langkah berjaga-jaga yang mesti diambil apabila menjalankan eksperimen ini.

[1 mark][1 markah]

(b) How can you ensure that all the oxide of metal M has been reduced?Bagaimanakah anda memastikan kesemua oksida logam M telah diturunkan?

[1 mark][1 markah]

(c) (i) Name two chemicals used to prepare hydrogen gas in the laboratory.Namakan dua bahan kimia yang digunakan untuk menyediakan gas hidrogen di

dalam makmal.

[1 mark][1 markah]

(ii) Write an equation for the reaction in (i).Tuliskan persamaan bagi tindak balas dalam (i).

[1 mark][1 markah]

(iii) Name a chemical used to dry hydrogen gas.Namakan bahan kimia yang digunakan untuk mengeringkan gas hidrogen.

(d) The table below shows the result of the experiment:Jadual di bawah menunjukkan keputusan eksperimen.

Mass of combustion tube + asbestos paperJisim tabung pembakaran + kertas asbestosMass of combustion tube + asbestos paper + oxide of metal M before heatingJisim tabung pembakaran + kertas asbestos+ oksida logam M sebelum pemanasanMass of combustion tube + asbestos paper+ metal M after heatingJisim tabung pembakaran + kertas asbestos+ logam M selepas pemanasan

= 39.25 g

= 47.95 g

= 44.95 g

(i) Determine the empirical formula of M oxide.Tentukan formula empirik oksida M.

[2 marks][2markah]

(ii) Write the chemical equation of the reduction of M oxide to metal M by using hydrogen gas.Tuliskan persamaan kimia bagi penurunan oksida M kepada logam M menggunakan gas hidrogen.

[2 marks][2markah]

(e) Can the empirical formula of magnesium oxide be determined by using the same arrangement of apparatus as above? Explain your answer.Bolehkan formula empirik bagi magnesium oksida ditentukan dengan menggunakan susunan radas yang sama seperti di atas? Jelaskan jawapan anda.

[2 marks][2markah]

SECTION CInstruction: Answer all questions in this section.

9. The empirical formula of magnesium oxide is determined by heating magnesium metal in air. A 20 cm long magnesium ribbon is cleaned with sand paper. An empty crucible with its lid is weighed. The magnesium ribbon is then placed in the crucible and the crucible with its contents is weighed again. The crucible is then heated strongly until the magnesium ribbon starts to burn. The lid of the crucible is opened and closed occasionally during the combustion of magnesium. After the combustion, the crucible and its contents are cooled and weighed again. The results are tabulated below:Formula empirik bagi magnesium oksida ditentukan melalui pemanasan logam magnesium dalam udara. Pita magnesium dengan panjang 20 cm dibersihkan dengan menggunakan kertas pasir. Sebuah mangkuk pijar dan penutupnya ditimbang. Mangkuk pijar itu kemudiannya dipanaskan dengan kuat sehingga pita magnesium mula terbakar. Penutup magkuk pijar dibuka dan ditutup dengan segera sekali sekala semasa pembakaran magnesium. Selepas pembakaran, mangkuk pijar dan kandungannya dibiarkan sejuk dan ditimbang semula. Keputusan dijadualkan di bawah:

Mass of empty crucible + lidJisim mangkuk pijar kosong dan penutupnyaMass of empty crucible + lid + magnesium ribbonJisim mangkuk pijar kosong dan penutupnya + pita magnesiumMass of empty crucible + lid + magnesium oxideJisim mangkuk pijar kosong dan penutupnya + magnesium oksida

= 43.72 g

= 48.52 g

=51.72 g

(a) Why must the magnesium be cleaned with sand paper?Mengapakah magnesium perlu dibersihkan dengan kertas pasir?

[1 mark][1 markah]

(b) Give a reason for opening the lid during combustion.Berikan satu sebab bagi pembukaan penutup mangkuk pijar semasa pembakaran.

[1 mark][1 markah]

(c) Why must the lid be closed immediately after it is opened?Mengapakah penutup mangkuk pijar perlu ditutup dengan segera selepas ia dibuka?

[1 mark][1 markah]

(d) How would you ensure that the magnesium is completely oxidized?Bagaimanakah anda memastikan magnesium telah dioksidakan dengan lengkap?

[1 mark][1 markah]

(e) From the results above, calculate the empirical formula of magnesium oxide.(O =16, Mg = 24)Daripada keputusan di atas, hitungkan formula empirik magnesium oksida.(O =16, Mg = 24)

[2 marks][2 markah]

10. An experiment was carried out to study the effect of concentration on the rate of reaction. 50 cm3 of 0.2 mol dm-3 sodium thiosulphate solution was poured into a conical flask. 5 cm3

of 2.0 mol dm-3 hydrochloric acid was added to the sodium thiosulphate solution. The stop watch was started. The flask was shaken and then placed on a piece of paper which was marked X. The flask was viewed from above as shown in the diagram below.Suatu eksperimen dijalankan untuk mengkaji kesan kepekatan terhadap kadar tindak balas. 50 cm3 0.2 mol dm-3 larutan natrium thiosulfat dituang ke dalam sebuah kelalang kon. 5 cm3 2.0 mol dm-3 asid hidroklorik ditambah ke dalam larutan natrium thiosulfat. Jam randik dimulakan. Kelalang digoncang dan diletakkan pada sekeping kertas yang ditanda X. Kelalang dilihat daripada atas seperti dalam rajah di bawah.

View from top of the conical flaskPandangan dari atas kelalang kon

The stop watch was stopped the moment the mark X ‘disappeared’ from view as shown in the diagrams above and the time of reaction recorded. The experiment was repeated by diluting the sodium thiosulphate solution as shown in the table below:Jam randik dihentikan apabila tanda 'X' tidak kelihatan lagi seperti dalam rajah di atas dan masa tindak balas dicatatkan. Eksperimen diulang dengan mencairkan larutan natrium thiosulfat seperti dalam jadual yang ditunjukkan di bawah.

ExperimentEksperimen

I II III IV V

Volume of 0.2 M of Na2S2O3 solution.0.2 M larutan Na2S2O3.

50 40 30 20 10

Volume of water /cm3

Isipadu air /cm30 10 20 30 40

Concentration of sodium thiosulphate solution / MKepekatan larutan natrium

0.2

thiosulfat / MVolume of 2.0 M HCl / cm3

Isipadu bagi 2.0 M HCl / cm3

5 5 5 5 5

Time,t /secMasa, t / saat

20.5 25.0 32.5 50.0 100.0

t

1 / sec-1

t

1 / saat-1

(a) Write the chemical equation for the reaction between sodium thiosulphate and hydrochloric acid.Tulis persamaan kimia bagi tindak balas antara natrium thiosulfat dan asid hidroklorik.

[1 mark][1 markah]

(b) Calculate the concentrations of sodium thiosulphate solution for the experiments II – IV.Hitungkan kepekatan larutan natrium thiosulfat bagi eksperimen II - IV.

[2 marks][2 markah]

(c)Calculate the values of

t

1 for each experiment

Hitungkan nilai bagi t

1 bagi setiap eksperimen.

[2 marks][2 markah]

(d) Plot a graph of concentration of sodium thiosulphate solution against time, t.Plotkan graf kepekatan larutan natrium thiosulfat melawan masa, t.

[3 marks][3 markah]

(e) What can you conclude from the graph in (d) above?Apakah kesimpulan yang anda boleh buat daripada graf dalam (d) di atas.

[1 mark][1 markah]

(f) (i)Plot a graph of concentration of sodium thiosulphate solution against

t

1.

Plotkan graf kepekatan larutan natrium thiosulfat melawan t

1.

[2 marks][2 markah]

(ii) From your graph, determine the time of reaction if sodium thiosulphate solution of concentration 0.1M is used in the reaction.Daripada graf anda, tentukan masa tindak balas jika larutan natrium thiosulfat dengan kepekatan 0.1 M digunakan dalam tindak balas ini.

[2 marks][2 markah]

(iii) What conclusion can you make from the graph above?Apakah kesimpulan yang boleh anda buat daripada graf di atas.

[2 marks][2 markah]

(g) Using the collision theory, explain how concentration affects the rate of reaction.Dengan menggunakan teori pelanggaran, terangkan bagaimana kepekatan mempengaruhi kadar tindak balas.

[3 marks][3 markah]

11. Two experiments are carried out separately:Dua eksperimen dijalankan secara berasingan:

Experiment I :Eksperimen I:

10 g of marble chips (excess) was added into 100 cm3 of hydrochloric acid with concentration X mol dm-3.10 g ketulan marmar (berlebihan) ditambah ke dalam 100 cm3 asid hidroklorik dengan kepekatan X mol dm-3.

Experiment II :Eksperimen II:

10 g of marble chips (excess) was added into 100 cm3 of hydrochloric acid with concentration Y mol dm-3. 10 g ketulan marmar (berlebihan) ditambah ke dalam 100 cm3 asid hidroklorik dengan kepekatan Y mol dm-3.

Both experiments are carried out at room temperature and pressure. The graphs of volume of carbon dioxide gas against time for both experiments are shown below:Kedua-dua eksperimen dijalankan pada suhu dan tekanan bilik. Graf isipadu gas karbon dioksida melawan masa bagi kedua-dua eksperimen ditunjukkan di bawah:

(a) Which of the two experiments uses hydrochloric acid solution of lower concentration? Explain your answer.Antara dua eksperimen tersebut yang manakah menggunakan larutan asid hidroklorik pada kepekatan yang lebih rendah?Jelaskan jawapan anda.

[2 marks][2 markah]

(b) Calculate the average rate of reaction for experiment I.Hitungkan purata kadar tindak balas bagi eksperimen I.

[1 mark][1 markah]

(c) (i) Calculate the number of mole of carbon dioxide gas collected in experiment II.(1 mole of gas occupies a volume of 24 dm3 at room temperature and pressure).Hitungkan bilangan mol gas karbon dioksida yang dikumpul dalam eksperimen II.(1 mol gas menempati isipadu 24 dm3 pada suhu dan tekanan bilik).

[1 mark][1 markah]

(ii) Calculate the concentration of the acid used in experiment II.Hitungkan kepekatan asid yang digunakan dalam eksperimen II.

[3 marks][3 markah]

(d) Suggest two other ways to increase the rate of reaction between the marble chips and the hydrochloric acid solutions.Cadangkan dua cara lain untuk meningkatkan kadar tindak balas antara ketulan marmar dan larutan asid hidroklorik.

[2 marks][2 markah]

(e) Explain why the total volume of carbon dioxide gas collected for both experiments is different?Jelaskan mengapa jumlah isipadu gas karbon dioksida yang dikumpul bagi kedua-dua eksperimen adalah berbeza?

[1 mark][1 markah]

12. The figure below shows the set-up of the apparatus of an experiment to determine the heat of displacement of copper by zinc. 50.0 cm3 of 0.2 mol dm-3 copper(II) sulphate solution was poured into a plastic cup. The initial temperature of the solution was

recorded. Excess zinc powder was added and the mixture was stirred. The maximum temperature of the mixture was recorded.Rajah di bawah menunjukkan susunan radas bagi eksperimen untuk menentukan haba penyesaran kuprum oleh zink. 50.0 cm3 0.2 mol dm-3 larutan kuprum(II) sulfat dituang ke dalam sebuah cawan plastik. Suhu awal larutan dicatatkan. Serbuk zink berlebihan ditambah dan campuran dikacau. Suhu maksimum campuran dicatatkan.

Result:Keputusan:

Initial temperature of copper(II) sulphate solution = 28oC Suhu awal larutan kuprum(II) sulfat = 28oC

Maximum temperature of copper(II) sulphate solution = 38oC Suhu maksimum larutan kuprum(II) sulfat = 38oC

(a) State two observations of the experiment other than the increase in temperature of the mixture.Nyatakan dua pemerhatian bagi eksperimen ini selain daripada kenaikan suhu dalam campuran.

[2 marks][2 markah]

(b) Write an ionic equation for the reaction occurring in the plastic cup.Tulis persamaan ionik bagi tindak balas yang berlaku dalam cawan plastik.

[1 mark][1 markah]

(c) Calculate the change of heat in the experiment.(Assuming the specific heat capacity of water is 4.2 J g-1 oC-1)Hitungkan perubahan haba dalam eksperimen ini.(Andaikan muatan haba tentu air ialah 4.2 J g-1 oC-1)

[1 mark][1 markah]

(d) Calculate the number of mole of copper displaced.Hitungkan bilangan mol kuprum disesarkan.

[1 mark][1 markah]

(e) Calculate the heat of displacement of copper.Hitungkan haba penyesaran kuprum.

[1 mark][1 markah]

(f) Draw the energy level diagram for the reaction.Lukiskan gambar rajah aras tenaga bagi tindak balas ini.

[2 marks][2 markah]

(g) A pupil repeats the experiment, replacing the zinc metal with metal X. The equation below shows the heat of displacement of copper by metal X.X(s) + CuSO4(aq) Cu(s) + XSO4(aq) H = -168 kJ mol-1

Predict the metal X.Choose from the list: Magnesium, aluminium and iron.Explain your answer.Sekumpulan pelajar mengulangi eksperimen ini, menggantikan logam zink dengan

logam X.Persamaan di bawah menunjukkan haba penyesaran kuprum oleh logam X.X(p) + CuSO4(ak) Cu(p) + XSO4(ak) H = -168 kJ mol-1

Ramalkan logam X.

[2 marks][2 markah]