1_format Pentaksiran Kimia Spm 2011 (1)

Teknik Menjawab Kimia / Chemistry

SPM 2011

nnAZ X /

electron (-)

proton (+)

neutron (0)

It’s like this

4541/2 CHEMISTRY Paper 2

A good chemistry student must have the following capabilities :

Able to relate the facts and concepts learnt. Able to use scientific skills Able to apply his/her knowledge in a new situation

To have these capabilities, you must :

Understand and remember important definitions/theories.

Know how to write chemical formulae and equations.

Understand and remember all aspects of an experiment.

Have a critical and analytical thinking to interpret and analyse graphs, diagrams, tables and chemical equations.

Be able to carry out calculations using the

concept of mole.

Strategy of Answering 4541/2 ZA-SMKATJ

2


FORMAT PENTAKSIRAN KIMIA/CHEMISTRY SPM 2005-2009

Paper Type of Question Number of Question Marks Time

4541/1Paper 1

Objective

A, B, C, D [Multiple choice] I, II, III, IV

A, B, C, D [Multiple combination]

4 choices of answer : A, B, C and D.

50(Answer all questions)

50 1 ¼ hour

4541/2Paper 2

Subjective

Consist of 3 Sections :

2 ½ hours

Section A : Structured items6

(Answer all questions)

60

Section B : Essay [Limited response items] 2(Answer any one) 20

Section C : Essay [Open response items] 2(Answer any one) 20

4541/3Paper 3

Subjective

Structural 1 or 2(Answer all)

50 1 ½ hoursEssay 1 or 2

(Answer any one)4541/4PEKA PEntaksiran Kerja Amali // Practical Assessment

TOPICS IN CHEMISTRYFORM CHAPTER TOPIC Note

4

1 Introduction to Chemistry2 The Structure of the Atom3 Chemical Formulae and Equations 4 Periodic Table of Elements5 Chemical Bonds6 Electrochemistry √7 Acids and Bases √8 Salts √9 Manufactured Substances in Industry

5 1 Rate of Reaction √2 Carbon Compounds √


3


3 Oxidation and Reduction √4 Thermochemistry √5 Chemicals for Consumers

THE STRATEGY OF ANSWERING CHEMISTRY PAPER 2

A UNDERSTANDING THE TASK OF THE QUESTION

Read carefully and understand the *task of the question.Underline the key words given in the question as a guide.

Plan your answer before writing.

Section A :

The answers may be : a number a word an equation a short phrase a few sentences

your answers should be simple and accurate. complete sentences are not required!

☺[ The marks allocated for each part is an indicator to the length of answer required ]

Section B & C [Essay] :The answers should be contain all the important points.

Only correct and complete answers will be given full marks.

Sometimes, your answers should include the following :

diagram/set-up of apparatus table graph working in calculations chemical equations

to support your answer!

☺[ The marks allocated for each part is an indicator to the length of answer required ]


4


*THE TASK OF THE QUESTION

Keyword Explanation

State Nyatakan

Short facts are required. No explanation is needed!

Example :State the common name of the element between group 2 and group 13.

Answer : Transition element. √

State the name Namakan

Write the name NOT the formula! No explanation is needed.

Example :Name the gas collected in the test tube at electrode X.

Answer : Oxygen √

[ NOT : O2 ]

Write Tulis

Shorts facts are required. No explanation is needed!

Example 1 :Write the electron arrangement for the magnesium atom.

Answer : 2.8.2 √

Example 2 :Write the formula of sodium sulphate.

Answer : Na2SO4 √

DefineTakrifkan

Give the meaning ofNyatakan maksud bagi

What is meant

Give the meaning of a term correctly, precisely and completely.

Example :What is the meaning of nucleon number?

Answer :


5


by // What is the meaning ofApakah yang dimaksudkan dengan

The total number of protons and neutrons found in the nucleus of an atom. √

[ NOT : protons + neutrons // p + n ]

State the observationNyatakan pemerhatian

Give the answer based on ‘what do you got?’ using our five senses.

Example :What would you observe at electrode Y?

Answer : A reddish-brown solid is deposited // Electrode Y becomes thicker. √

[ NOT copper metal is formed ]

Explain Terangkan / Jelaskan

Give the reasons to describe the happening / fact / phenomenon / observation.

Example :

Explain the above statement based on the size of the reactants.

Calculate Hitungkan Show all the workings in calculation

Example :

When 10 cm3 of 0.5 mol dm-3 Na2SO4 solution is added to excess Pb(NO3)2 solution, a white precipitate is formed.Calculate the mass of precipitate formed.

Answer :

Number of mole of Na2SO4= √= 0.005 mol

√

From the equation above :1 mol of Na2SO4 produced 1 mol of PbSO4

Therefore :0.005 mol of Na2SO4 produced 0.005 mol of PbSO4 √


6

One kilogramme of meat, cut into big pieces, takes a longer time to cook compared to one kilogramme of meat cut into small pieces.

Na2SO4 + Pb(NO3)2 → 2NaNO3 + PbSO4

White precipitate

1 mol 1 mol


Mass of PbSO4 = 0.005 × [ 207 + 32 + 4(16)]= 1.515 g √

Chemical testUjian kimia

Give the reagent, procedure and observation.

Example :Describe a chemical test to identify the iron(III) ion, Fe3+.

Answer :

Procedure : 1. 5 cm3 of the solution that contains Fe3+ ion is poured into a

test tube. 2. 5 cm3 of 2.0 mol dm-3 sodium hydroxide solution is added

into the test tube. √Observation :

Brown precipitate is formed. √

Compare Bandingkan

Give both the similarities and differences between two terms / phenomena / subjects.

Example :Compare the cleansing effects between soap and detergent.

ContrastNyatakan perbezaan

Give the differences between two terms / phenomena. [ Menyatakan perbezaan kedua-dua perkara yang sepadan]

Example :Explain the differences in the melting and boiling points of ionic and covalent compounds.

1.

Describe Huraikan

Write in detail what is being done, observed or deduced.

Example :Describe the steps that should be taken to ensure that all the air in the combustion tube has been expelled.


7

reagent


Describe an experimentHuraikan satu eksperimen

Your description must include the following items :

List of Apparatus & Substances / Materials

Diagram [ set-up of apparatus for the experiment ] (wherever suitable to support your answer!)

Procedure Follow the correct order. State the quantity of chemical such as :

solution » volume and concentration(eg : 100 cm3 of 2.0 mol dm-3 copper(II) sulphate solution) solid » mass, spatula, ….(eg : 2.0 g marble chips, 1 spatula zinc powder, 10 cm

magnesium ribbon, …..) Include Precautionary steps (if present)

Observation / Result Relevent table

Analysis of the observation / result draw/sketch a graph steps of calculation write the equation for the reaction

Conclusion

PredictRamalkan

Make a deduction or logical conclusion based on the given information or your own knowledge or both.

Experiment I is repeated. Sulphuric acid is replaced by hydrochloric acid of the same concentration.Predict the volume of hydrochloric acid required for a complete reaction.

DiscussBincangkan Give all important points and discuss each one critically.

Example :Discuss why lead(II) bromide in solid state does not conduct electricity while molten lead(II) bromide does.

Answer :Lead(II) bromide is an ionic compound.In solid state, Pb2+ ions and Br- ions are held together by strong


8


electrostatic forces. These ions do not move freely. √In molten state, Pb2+ ions and Br- ions are free to move. √

B SKILLS // CONCEPTS

A good chemistry student must have the following skills :

SKILL EXPLANATION

Draw a diagram / set-up of apparatusMelukis gambar rajah / susunan radas

Diagram should be drawn neatly and correctly in pencil.All diagrams should be :

*Funtional : (berfungsi) Gabus tidak masuk ke dalam

Tidak bocor atau tersumbatLarutan dilorekBuret disokong/dipegang dengan pemegang retortTabung didih dipegang dengan pemegang apabila dipanaskan

Labelled : (berlabel)Bahan tindak balas dilabel dengan nama/formulaAlat radas utama dilabelProses pemanasan dilukis anak panah ke atas dan dilabel panaskan/haba

Draw a diagram of particles arrangementMelukis gambar rajah susunan zarah

Diagram of particles arrangement in solid state :

Closely packed together In orderly manner Minimum; 3 rows × 3 columns


9

C4H8 gas

Glass wool soaked in butan-1-ol

waterHeat

Porcelain chips

alloy


Write the observation

Solid (precipitate / deposits) state the colour Precipitate dissolved / undissolved in excess certain reagent. Gas state the colour (if any) or the property of the gas.

Solution For colour changes, initial colour and end colour must be mention.

Describe a chemical test Describe in simple procedure ;

added, heated, dropped, etc

Name and state the reagent ; Glowing wooden splinter, lighted wooden splinter, sodium

hydroxide solution, acidified potassium manganate(VII) solution, etc

Observation that occurs correctly ;Example :

Chemical Test For GasesGas Procedure Observation

Oxygen, O2Lower a glowing wooden splinter into the test tube.

The glowing wooden splinter light up.

Hydrogen, H2

Bring a lighted wooden splinter to the mouth of the test tube.

A ‘pop’ sound will be heard.


10

Not accurate Accurate √Colour : transparent Colourless

Bromine gas is release A brown gas is released

Copper is deposited at the cathode

A brown solid/metal is deposited at the cathode // cathode becomes thicker

Hydrogen gas is produced Gas bubbles are released

Litmus paper turns blue Red litmus paper turns blue

Becomes colourless / decolourise

Blue colour becomes colourless // Blue colour bleaches/ decolourise // The intensity of the blue colour decreases

No reaction Unchanged

Galvanometer/ammeter/ voltmeter deflected

Galvanometer/ammeter/voltmeter gives/ shows the reading


Carbon dioxide, CO2

Bubble/flow the gas produced into lime water.

The lime water turn cloudy/milky/chalky.

Draw a diagram of electron arrangement of compounds Melukis gambar rajah susunan elektron bagi sebatian

Ionic compound : Number of ions combined is correct. All ions are labelled Charge of each ions are correct.

Covalent compound : Number of atoms combined to form the compound must be

correct. All atoms must be labelled. Sharing of electrons must be correct.


11

X Y X

+ 2- +

W Z

Z

Z

Z


Draw /Sketch a gr a ph Melukis /Melakar graf

You have to consider 4 following items :

Axes must be labelled with quantity and unit.

Scale for all axes must be suitable. [ Minimum ½ of the graph is used ] [No need if you sketch the graph!]

All Points /coordinates are transferred correctly.

Curve or straight line of the graph must be draw smoothly.

Draw the direction of electron flow Melukis gambar rajah arah pengaliran elektron

Draw the arrow at the connecting wire.[Tidak boleh merentasi/melalui larutan]

Write the equationMenulis persamaan

All equations must be :

Formulae of reactants and products are correct Balanced equation.

Calculate Hitungkan

Show all the working of calculations.The value of the answers must be correct and have unit.

Colour The colour of all chemicals must be determine correctly.

For colour changes , initial colour and end colour must be mention.


12


Draw an Energy Profile diagramMelukis gambar rajah aras tenaga

The Energy Profile diagram must include the following items :

Axis/Vertical line with the arrow The axis is labelled with Energy Two horizontal lines that shows the different energy

levels. Reactants and products at the correct level. Formulae of the reactants and products are correct. Value of ΔH and the sign ( + or - ) are correct.

Example :

2C3H7OH + 9O2

H = - 1932 kJ mol-1

6CO2 + 8H2O


13

Energy


C PERINGATAN !

1 Persamaan mesti betul dan seimbang!

2 Dapat membezakan jenis-jenis persamaan :

Chemical equation [ Persamaan kimia bagi tindak balas ] Half equation [ Setengah persamaan ] Ionic equation [Persamaan ion ] Overall ionic equation [Persamaan ion keseluruhan ]

3 Apabila melukis gambar rajah susunan radas, pastikan :

Functional [ Berfungsi ] Labelled [ Berlabel ]

4 Apabila melukis graf, beri perhatian kepada :

Paksi berlabel // Labelled axis Skala yang sesuai // Suitable scale Titik/koordinat dipindahkan dengan betul // All points are at correct

coordinates Garis lurus/lengkung yang licin // Smooth line

5 Semua jalan kerja dalam penghitungan/pengiraan ditunjukkan.Unit mesti disertakan pada jawapan.

6 Warna bahan kimia mesti tepat!

7 Bagi perubahan warna, mesti dinyatakan warna asal dan warna akhir .

8 Ejaan bagi nama bahan kimia dan istilah mesti betul!

9 Perlakuan-perlakuan (kata kerja) yang penting dalam huraian eksperimen mesti dinyatakan.

10 Dalam huraian kaedah eksperimen, beri perhatian kepada :

Langkah-langkah yang berturutan/berkesinambungan Kuantiti bahan yang digunakan mesti dinyatakan (g, cm, cm3, spatula)


14

Formulae of the reactants and products must be correct!


Keadaan bahan kimia yang digunakan mesti dinyatakan (solid, solution, powder, granule, crystal)

Bagi larutan (solution), mesti dinyatakan isipadu (volume) dan kepekatannya (concentration).

Alat penyukat dan spesifikasinya perlu diambil kira.

Contoh :

25 cm3 of 1.0 mol dm-3 copper(II) sulphate solution was measured using a 50 cm3 measuring cylinder and was poured into a 100 cm3 beaker.

11 Sedari bahawa Reactivity Series (Siri Kereaktifan) adalah berbeza daripada Electrochemical Series (Siri Elektrokimia)!

12 Sesuatu pernyataan mesti tepat!

Contoh :

Electron arrangement of sodium element is 2.8.1 [ salah ]☺ Electron arrangement of sodium atom is 2.8.1 [ betul ]


15

quantity physical stateconcentration

verb

apparatus and its specification


D KESILAPAN // KELEMAHAN CALON-CALON DALAM MENJAWAB SOALAN KIMIA Kertas 2

Soalan Struktur (Section A ) 1 Tidak memahami kehendak soalan [Tidak arif tentang kata tugas soalan].

Menjawab mengikut kefahaman sendiri!

2 Memberi jawapan yang terlalu panjang [ Sengaja memanjangkan jawapan dengan menyalin semula sebahagian soalan!]

3 Memberi lebih daripada satu jawapan dan jawapan yang bercanggah antara satu sama lain!

4 Bagi soalan penghitungan, jawapan yang diberi tanpa unit ATAU unit salah!

5 Ejaan yang salah pada nama bahan kimia atau istilah.

Soalan Esei (Section B and C )

1 Jawapan yang diberi terlalu umum, tiada isi.

2 Jumlah isi yang diberi tidak sepadan dengan jumlah markah yang diperuntukkan.

3 Jawapan yang diberi tidak disertakan dengan gambar rajah, jadual keputusan, lakaran graf, persamaan tindak balas dan sebagainya sebagai pelengkap .

4 Fakta yang dipersembahkan tidak tersusun.

5 Terdapat fakta yang bercanggah antara satu sama lain.

6 Tulisan yang sukar dibaca!

Kesalahan-kesalahan lain (Terdapat dalam soalan Struktur dan Esei)

1 Menulis persamaan dengan formula bahan dan hasil yang tidak betul atau persamaan yang tidak seimbang! [ disebabkan tidak tahu formula sebatian yang betul ]


16


2 Tidak dapat menyatakan warna bahan kimia dengan tepat. Jika perubahan warna, tidak menyatakan warna asal.

3 Apabila melukis gambar rajah, biasanya gabus masuk ke dalam tabung uji/ kelalang kon. [ Radas tidak berfungsi! ]

4 Langsung tidak menjawab soalan yang melibatkan penghitungan. [ Tidak menguasai konsep mol! ]

5 Tidak menitikberatkan perlakuan-perlakuan penting dalam huraian kaedah eksperimen.

The sulphuric acid was poured quickly and carefully into the conical flask.

The water bath was heated slowly until the temperature reached 60 OC. The naphthalene was stirred slowly, carefully and continuously with a

thermometer.

6 Keliru antara pemerhatian (observation) dan kesimpulan (conclusion)!*Memberi kesimpulan (conclusion) sebagai jawapan untuk pemerhatian.

Example :State the observation when zinc powder is added into dilute hydrochloric acid in a test tube.

Given answer : Hydrogen gas is liberated.

☺Correct answer :Effervescence occurs // A colourless gas is produced. √

7 Apabila melukis graf, paksi tidak dilabel atau label tiada unit!

8 Dalam huraian kaedah eksperimen, kuantiti dan keadaan bahan kimia yang diguna tidak dinyatakan.

9 Menumpukan kepada satu perkara sahaja apabila menjawab soalan yang melibatkan perbandingan atau perbezaan antara dua perkara.

10 Tidak memberikan contoh yang spesifik apabila diminta.

11 Menggunakan singkatan istilah dalam menjawab soalan.Contoh : ES (Electrochemical Series), RS (Reactivity Series), RAM (Relative

atomic mass)


17


The END


18

1_format Pentaksiran Kimia Spm 2011 (1)

Documents

Transcript of 1_format Pentaksiran Kimia Spm 2011 (1)