Percubaan Kimia Johor 2010 Kertas 2 With Answer

Nama : . Kelas: .

JABA TAN PELAJARAN NEGERI JOHOR

PEPERIKSAAN PERCUBAAN SPM 2010CHEMISTRYKertas 2

August

2Y2jamDua jam tiga puluh minit

JANGAN BUKA KERTAS SOALAN 1Nl SEHINGGA DIBERITAHU

4541/2

1. Tu/iskan nama dan tingkatan padaruang yang disediakan.

2. Kertas soa/an ini ada/ah da/amdwibahasa.

3. Soa/an da/am bahasa /nggerismendahului soa/an yang sepadandalam bahasa Melayu.

4. Ca/on dibenarkan menjawabkeseluruhan atau sebahagiansoalan sama ada da/ambahasa/nggeris atau bahasaMelayu.

5. Calon dikehendaki membacamaklumat di halaman be/akangkertas soalan ini.

Untuk Kegunaan Pemeriksa

Bahagian

SoalanMarkah

MarkahPenuh

Diperoleh

1

10

2

10

310

A 410

5

10

6

10

7

20B 8

20

9

20C 10

20

Jumlah

Kertas ini mengandungi 28 halaman bercetak

SULIT 2

Section ABahagianA

[60 marks][60 markah]

Answer all questions in this section.Jawab semua soa/an da/am bahagian ini.

1 Diagram 1 shows three industrial processes involved in manufacturing ammoniumI sulphate.

Rajah 1menunjukkan tiga proses industri da/am penghasi/an ammonium su/fat.

Process I

Sulphur ISulfur

Sulphur dioxide ISulfur dioksida

Sulphur trioxide ISulfur trioksida

Nitrogen INitrogen

Oleum IOleum

Sulphuric Acid IAsid su/furik

Process III

Ammonium sulphate IAmmonium sulfat

Diagram 1Rajah 1

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SULIT

Hydrogen IHidrogen

1

l Process 11IAmmonia IAmmonia

1

I

~IT 3

From the flow chart shown in Diagram 1. answer the following questions.Dari carta alir pada Rajah 1, jawab soalan berikut.

(a) For Process I.Untuk proses I.

(i) Name the industrial process of producing sulphuric acid.Namakan proses industri untuk membuat asid sulfurik

[ 1 mark]

(ii) State how to produce sulphur dioxide from sulphur.Nyatakan bag aim ana untuk membuat sulfur dioksida dari sulfur

[ 1 mark]

(iii) Write the chemical formula of sulphur trioxideTuliskan formula kimia untuk sulfur dioksida

[ 1 mark]

(iv) Sulphur trioxide dissolves in compound M to produce oleum. What iscompound M?Sulfur trioksida melarut dalam sebatian Muntuk menghasilkan oleum.Apakah sebatian M ?

[ 1 mark](v) State how sulphuric acid is produced from oleum.

Nyatakan bagaimana asid suffurik di hasilkan dari oleum

[ 1 mark](vi) Sulphuric acid produced is mixed with water in a beaker. State the

observation if a piece of marble is dropped into the beaker.Asid sulfurik yang terhasil dilarutkan ke da/am bikar berisi air.Nyatakan pemerhatian jika sebutir marmar dimasukkan ke dalam bikaritu.

[ 1 mark]

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SULIT 4

(b) Name a suitable catalyst for Process 11.Namakan satu mangkin yang sesuai untuk Proses 1/.

[1 mark]

(c) For Process Ill,Untuk Proses Ill,

(i) Write the chemical equation for the reaction of ammonia with sulphuricacid.Tuliskan persamaan tindak ba/as untuk tindak ba/as ammonia denganasid su/furik.

[2 mark]

(ii) State one use of ammonium sulphate in daily life.Nyatakan satu kegunaan ammonium su/fat da/am kehidupan seharian

[1 mark]

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~ULIT 5

2 Graph 2 shows the temperature against time when solid P is heated.Graf 2 menunjukkan gmf suhu melawan masa bagi pemanasan pepejal P.

Temperature 1°CSuhuloC

200 +----------------------------------------------------

136

Time/sMasa/s

Graph 2Graf2

(a) Based on Graph 2 • answer the following questions:Berdasarkan Graf 2, jawab soalan-soalan berikut :

(i) What is meant by melting point?Apakah yang dimaksudkan dengan takat lebur ?

[1 mark]

(ii) State the melting point of substance P .Nyatakan takat lebur bahan P.

[1 mark](Hi) State the physical state of P from time t1 to h.

Nyatakan keadaan fizik P dari masa t1 hingga t2.

[1 mark]

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SULIT 6

(iv) Explain why the temperature remains constant from time t1 to t2.Terangkan kenapa suhu tidak berubah dart masa t1 hingga h.

............., , [2 marks]

(v) Diagram 2 shows the set-up of apparatus used by a student todetermine the melting point of substance P.Rajah 2 menunjukkan susunan radas yang digunakan o/eh seorangpe/ajar untuk menentukan takat /ebur bahan P.

EthanolEtano/

SolidPBahanP

Diagram 2Rajah 2

Identify one mistake in the diagram. Explain why.Kenalpasti satu kesilapan da/am rajah tersebut. Je/askan mengapa.

[2 marks]

~ ..

(b) When solid iodine is heated. it changes to purple fume.Apabila pepeja/ iodin dipanaskan ) la bertukar ke wasap ungu.

(i) Name the process involved.Namakan proses yang terfibat.

[1 mark]

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~ SULIT

(ii)

7

Name one isotope of iodine and state its use.Namakan satu isotop untuk iodin dan nyatakan kegunaannya .

............................................. .[2 marks]

3 Diagram 3 shows the set up of apparatus to investigate the electrolysis of sodiumchloride solution.

Rajah 3menunjukkan susunan radas untuk mengkaji elektrolisis larutan natriumklorida. Gas yang terkumpul pada elektrod Y berwama kuning dan melunturkanwama kertas litmus biru lembab.

Greenish yellow gasGas berwarna kuningkehijauan

Carbon electrode XE1ektrod karbon X

Sodium chloride solutionLarutan natrium klorida

Carbon electrode YKarbon e'ektrod Y

Diagram 3Rajah 3

(a) (i) What is meant by anion?Apakah yang dimaksudkan dengan anion?

[1 mark](ii) Write the formulae for all anions that are present in sodium chloride

solution.

Tuliskan formula bagi semua anion yang hadir dalam larutan natriumklorida.

[1 mark]


-------- ---_ ...~-_ .._-

SULIT 8

(Hi) The gas collected at electrode X decolourises a damp blue litmuspaper. Name the gas.Gas yang terkumpul pada elektrod X melunturkan kertas litmus birulembap. Namakan gas itu.

[1 mark](b) By referring to diagram 3 •

Dengan merujuk kepada Rajah 3,

(i) Which electrode is the cathode?Elektrod yang manakah merupakan katod ?

[1 mark]

(ii) Write the half-equation for the reaction at the cathode.Tuliskan persamaan setengah bagi tindak balas di katod.

[1 mark]

(iii) Describe a test to identify the gas collected at the cathode.Huraikan satu ujian untuk mengenalpasti gas yang terkumpul di katod.

[2 marks]

(c) The experiment is repeated by using 0.001 mol dm-3 sodium chloridesolution.

Eksperimen ini diulangi dengan menggunakan larutan natrium klorida0.001 mol dm'3

(i) Name the ion that is selectively discharged at the anode.Namakan ion yang didiscas secara pilihan di anod.

[ 1 mark]

(ii) Give a reason for Y9ur answer in (c)(i)Berl alasan bagi jawapan anda di (c)(i)

4541/2 © 2010 Hakcipta Jabatan Pelajaran Negeri lohorSULIT

9

[ 1 mark]

(iii) Name the gas collected at the anode.Namakan gas yang terkumpu/ di anod.

[1 mark]

4 Table 4 shows the molecular formulae and observations for three compounds whenthey react with bromine water.Jadual4 menunjukkan formula molekul dan pemerhatian bagi tiga sebatian apabilabertindakbals dengan air bromin.

Compound Molecular Formula ObservationSebatian

Formula Molekul Pemerhatian

p

IBrown colour is decolourised

IC2H4IWarna perang menjadi tidak berwama

I

II

Q

Brown colour remains

C2HsWarna perang tidak berubah

R

C4H10............................................. " .......

Tabie4Jadua/4

(a) Name the homologous series for these compounds.Namakan siri hom%g bagi sebatian-sebatian ini.

i) Compound PSebatian P

Compound QSebatian Q

[2 marks]

ii) What is the general formula for the homologous series of compoundR?

Apakah formula am bagi siri homolog sebatian R?

...... ~ , , , .

[ 1 mark J


SULIT 10

iii) Complete the observation for compound R in Table 4.Lengkapkan pemerhatian untuk sebatian R da/am Jadua/ 4.

[1 mark]

iv) Name a substance that can replace bromine water.Namakan satu bahan lain yang bo/eh menggantikan air bromin.

[ 1 mark]

v) Explain why compound P is chemically more reactive than compoundQ.Je/askan mengapa sebatian P /ebih reaktif secara kimia berbandingsebatian Q.

[ 1 mark](b) Compounds P and Q can undergo complete combustion to form gas X and

water.

Sebatian P dan Q bo/eh menga/ami pembakaran /engkap untuk menghasi/kangas X dan air.

i) Name gas X.Namakan gas X.

[ 1 mark]ii) Write a balanced chemical equation when compound P or Q reacts

with oxygen.Tu/is persamaan kimia yang seimbang apabila sebatian P atau Qbertindak ba/as dengan oksigen.

[ 1 mark]

Hi) Compare the sootiness of the flame when compound P and Q areburnt in the air. Explain why.Bandingkan keje/agaan nya/aan apabi/a sebatian P dan Q terbakar diudara. Terangkan mengapa.

[2 marks]

4541/2 © 2010 Hakcipta Jabatan Pelajaran Negeri Johor

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~LIT 11

5 Diagram 5 shows the set-up of apparatus to study the electron transfer at a distance.Rajah 5 menunjukkan susunan radas eksperimen untuk mengkaji pemindahanelectron pada satu jarak.

'''"

Carbon electrode XElektrod karbon X

Iron (H) sulphatFerum (II) su?fat

Carbon electrode YElektrod karbon Y

Acidified potassium manganate(VII) solutionLarutan kalium manganat (VII)berasid

\&~jJ.. - - ....-::::- -::::- Dilute

-::::::~::::::-:-- Sulphuric acidA.'dd sulfurik

Diagram 5Rajah 5

(a) What is the function of dilute sulphuric acid?Apakah fungsi asid sulfurik cair?

[1 mark]

(b) (i) State the observation at carbon electrode X.Nyatakan pemerhatian di elektrod karbon X.

[1 mark](ii) Write the half equation for the reaction in (b) (i)

Tuliskan persamaan setengah untuk tindak balas di (b) (i).

[2 marks]

(iii) Describe a confirmatory test for the product formed at carbon electrodeX.

Huraikan satu ujian pengesahan untuk hasil yang terbentuk di elektrodkarbon X.

[2 marks]

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SULIT 12 ".:...----

(c) (i) State the observation at carbon electrode Y.Nyatakan pemerhatian di elektrod karbon Y.

[1 mark]

(ii) What is the role of acidified potassium manganate (VII) solution in theexperiment?Apakah peranan larutan kalium manganat (VII) berasid da/ameksperimen ini ?

[1 mark]

(iii) Give a reason for your answer in (c) (ii).Berikan satu penjelasan untukjawapan anda pada (c) (ii).

[1 mark]

(d) Suggest another reagent that can replace acidified potassium manganate (VII)solution.

Cadangkan satu reagen lain yang baleh menggantikan larutan kaliummanganat (VII) berasid.

[1 mark]


~ULIT 13

6 Natural rubber is obtained from latex secreted by rubber tree. Latex is a white milklike fluid. Table 6 shows the results of latex coagulation.Getah asli dipero/ehi daripada /ateks yang didapati dari pokok getah. Susu getahmerupakan cecair yang berwama putih seakan susu. Jadua/6 menunjukkankeputusan pembekuan susu getah.

Procedure ObservationProsedur

Pemerhatian

X solution is added to latex

Latex coagulates immediatelyLarutan X ditambah kepada susu getah

Susu getah membeku dengan cepat

Latex is exposed to the air

Latex coagulates slowly

Susu getah dibiarkan terdedah di udara

Susu getah membeku dengan

per/ahan

Table 6Jadua/6

(a) Based on the Table 6, answer the following questions.Berdasarkan Jadua/ 6, jawab soa/an-soa/an berikut.

i} What is solution X ?Apakah /arutan X?

[ 1 mark]

ii) The coagulation of latex will also occur when it is exposed to air.Explain why this happens.Proses pembekuan susu getah juga berlaku apabi/a ia terdedahkepada udara. Je/askan mengapa ini terjadi.

[1 mark]iii) Suggest a solution that can be used to prevent latex from coagulating.

Cadangkan satu /arutan yang bo/eh digunakan untuk mengha/angpembekuan susu getah.

[1 mark]

b) During the preparation of soap, a concentrated alkali X is added to oil or fat.The mixture is heated and then sodium chloride is added. The generalequation for this reaction is shown below.Semasa proses pembuatan sabun, farutan a/kali pekat X di tambah kepadaminyak atau /emak. Campuran kemudian di panaskan bersama dengannatrium kforida. Persamaan tindak ba/asnya ada/ah seperti di bawah.

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SULIT

SULIT 14

0 011

11

CH2-O-C-R1CHz-OHRj-C-O-Na+

0

011

1\

CH-O-C-Rz+alkaliX ~ CH- OH+ Rz-C- O-Na+

0

011

11

CH2-O-C-R3CH2-0HR3 -C-O-Na+

Oil or fat

GlycerolSoaps

Based on the equation above. answer the following questions.Berdasarkan persamaan di atas, jawab soa/an -soa/an berikut.

i} What is the name of the process?Apakah nama proses tersebut?

[ 1 mark]

ii) What is alkali X ?Apakah alkali X ?

[1 mark]

iii) Why is sodium chloride solution added to the mixture?Mengapakah larutan natrium k/orida ditambahkan kepada campuran?

[1 mark]

iv) Describe briefly the cleansing action of soap.Huraikan dengan ringkas tindakan pembersihan oleh sabun

[2 marks]


(

~LIT

c)

15

Diagram 6 shows the structural formulae of two cleansing agents X and Y.Rajah 6 menunjukkan formula struktur bagi dua agen pembersih X dan Y.

Cleansing agent X:Agen pembersih X :

Cleansing agent Y:Agen pembersih Y:

Diagram 6Rajah 6

Based on Diagram 6, compare the effectiveness of cleansing action of agentY to agent X. Explain why.Berdasarkan Rajah 6, bandingkan keberkesanan tindakan pembersihan agenpencuci Y berbanding agen X. Terangkan mengapa.

i.

ii.

[2 marks]

[Libat sebelab4541/2 © 2010 Hakcipta Jabatan Pelajaran Negeri JohorSULIT

SULIT 16

Section BBahagianB

[20 marks]

Answer anyone question from this section.Jawab mana-mana satu soa/an daripada bahagian ini.

7 Diagram 7 shows parts of the Periodic Table of elements.Rajah 7 menunjukkan sebahagian unsurda/am Jadua/ Berka/a.

1 2 13 14 15 16 17 18r--- -C

0Mg

AICl

Diagram 7Rajah 7

(a) Write the electron arrangements for aluminium ion and oxide ion.Tuliskan susunan e/ektron bagi ion aluminium dan ion oksida

[2 marks]

(b) Describe the formation of the following chemical bonds and draw the electronarrangement of compounds formed.Huraikan pembentukan bagi ikatan kimia berikut dan /ukis susunan e/ektronbagi sebatian yang terbentuk.

(i) Ionic bond between magnesium atom and chlorine atom./katan ionik di antara atom magnesium dengan atom k/orin.

[5 marks]

(ii) Covalent bond between carbon atom and chlorine atom./katan kova/en di antara atom karbon dengan atom k/orin.

[5 marks](c) Explain each of the following statements.

Terangkan setiap pemyataan berikut.

(i) Compound formed in (b)(i) can conduct electricity in the molten statewhile compound formed in (b)(ii) cannot conduct electricity in anystate.Sebatian yang terbentuk da/am (b)(i) bo/eh mengkonduksikan e/ektrikda/am keadaan /eburan man aka/a sebatian yang terbentuk da/am(b)(ii) tidak dapat mengkonduksikan e/ektrik da/am semua keadaan.


17

[4 marks]

(ii) The melting and boiling points for compound in (b) (i) is higher thancompound in (b)(ii).Takal /ebur dan takat didih bagi sebatian da/am (b)(i) lebih tinggidaripada sebatian da/am (b)(ii).

[4 marks]

8 Table 8 shows the heat of combustion of the first five alcohols.

Jadual 8menunjukkan haba pembakaran unluk lima a/kohol yang pertama.

Alcohol/ Molecular Formula /Heat of Combustion / I

Alkohol

Formula mo/ekulHaba Pembakaran

kJ mor1Methanol Metano/

CHsOH- 715

EthanolElano!

C2HsOH- 1376

Propanol

CSH70HPropanol

- 2017

Butanol

C4HgOHIButanol

- 2675

Pentano!,Pentanol

ICSH110H mI

I

Table 8Jadua!8

The chemical equation for the combustion of ethanol is as below.Persamaan kimia bagi pembakaran etano! ada!ah seperti di bawah.

~H = -715 kJ mol-1

(a) Based on the equation above, state the meaning of heat of combustion ofethanol.

Berdasarkan persamaan kimia di atas, nyatakan maksud haba pembakaranbagi elanol.

[2 marks](b) Based on Table 8 I

Berdasarkan Jadual 8,

(i) Draw a graph of magnitude of heat of combustion against the numberof carbon atoms.

Lukis graf magnitud haba pembakaran melawan bilangan atomkarbon.

[3 marks]

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SULIT 18

(ii) State the relationship between the number of carbon atoms permolecule of alcohol to the magnitude of the heat of combustion.Nyatakan hubungan di antara bi/angan atom karbon per mo/eku/alkohol kepada magnitud haba pembakaran.

[ 1 mark]

(Hi) From the graph, predict the heat of combustion of pentanol in kJ mol .,Daripada graf, rama/kan haba pembakaran pentanol da/am kJ mort

[2 marks]

(c) Compare the heat of combustion between ethanol and butanol.Explain why there is a difference in the heat of combustion between ethanoland butanol.Bandingkan haba pembakaran etanol dengan butanol.Terangkan mengapa terdapat perbezaan di antara haba pembakaran etanoldan butanol.

[4 marks]

(d) Diagram 8 shows the energy level diagram of the heat of combustion ofethanol.Rajah 8 menunjukkan gambarajah aras tenaga bagi haba pembakaran etanol.

EnergyTenaga

LiH = -715 kJ mol"

Diagram 8Rajah 8

(i) Give four information that you can obtain from Diagram 8.Serikan em pat maklumat yang boleh diperoleh daripada Rajah 8.

[4 marks](ii) Calculate the energy released if 6.9 grams of ethanol is burnt

completely in air.Kira haba yang di bebaskan jika 6.9 gram etanol di bakar dengan/engkap di da/am udara.

[4 marks]


lI

~ULIT 19

Section CBahagian C

[20 marks]

Answer anyone question from this section.Jawab mana-mana satu soalan daripada bahagian ini.

9 (a) By using suitable example, explain what are meant by empirical formula andmolecular formula.

Dengan menggunakan contoh yang sesuai, terangkan apa yang dimaksudkandengan formula empirik dan formula molekul.

[3 marks]

(b) The information below is for compound QMaklumat berikut adalah bagi sebatian Q.

• CarbonKarbon

• HydrogenHidrogen

• OxygenOksigen

40.00%

6.66%

53.33%

• Relative molecular mass 180Jisim molekul relatif

Based on the information of compound Q, determine:Berdasarkan maklumat bagi sebatian Q, tentukan:

(i)

(ii)

The empirical formulaFormula empiriknya

The molecular formula

Formula molekulnya[ Relative atomic mass: C,12; H,1; 0,16][ Jisim atom relatif: C, 12; H,1; 0,16]

[5 marks]


[Lihat sebelah

SULIT 20

(c) Diagram 9 shows the set-up of apparatus to determine the empirical formula of twodifferent compounds.Rajah 9 menunjukkan susunan radas bagi menentukan formula empirik duasebatian yang berlainan.

Metal

Logam

Method IKaedah I

Method 11Kaedah 11

Metal oxide I Oksida logam

--+~=~ -=~Dry hydr::·::l.;:·· "--.. Asbestosgas I Gas paperHidrogen Heat I Kertas

kering panaskan asbestos

Table 9

Rajah 9

(i) Explain why method 11is not suitable to determine the empirical formula ofmagnesium oxide?Terangkan mengapa kaedah 11tidak sesuai bagi menentukan formula empirikbagi magnesium oksida?

[1mark](ii) Suggest one metal oxide in method 11.

Cadangkan sa tu oksida logam dalam kaedah 11.

[1 mark]

(iii) Using a suitable example, describe a laboratory experiment to determine theempirical formula of an oxide of a reactive metal. Your explanation shouldinclude:

Dengan menggunakan contoh yang sesuai, huraikan suatu eksperimen dimakmal untuk menentukan formula empirik bagi suatu oksida logam reaktif..Penerangan anda mestilah meliputi :

• Procedure of the experimentProsedurbagieksperimen

• Tabulation of data

Penjadualan data

[10 marks]


~LIT 21

10 (a) Table 10 shows different concentrations of hydrochloric acid and thecorresponding pH values.Jadua/ 10 menunjukkan kepekatan berlainan bagi asid hidrokforik dan ni/ai pHyang sepadan. .

Hydrochloric Concentration of hydrochloric acidAcid

Kepekatan asid hidrok/orikpHAsid hidrok/orik

Imol dm-3

A

0.0013I iB

I0.01 2I

!

,i C

0.11

D

10

Table 10Jadua/10

(i) Based on Table 10, state the relationship between the concentration ofhydrochloric acid and the pH value.Berdasarkan Jaduaf 10, nyatakan hubungan antara kepekatan asidhidrok/orik dan ni/ai pH.

(ii) Explain your answer in a (i) by referring to the number of hydrogen ionspresent in the acid.Je/askan jawapan anda di a (i) dengan merujuk kepada bilangan ionhidrogen yang terdapat dafam asid itu.

(iii) Arrange the hydrochloric acids in Table 10 according to increasing orderof acidity.Susun asid hidrok/orik da/am Jaduaf 10 menurut susunan menaikkeasidan.

[4 marks]


SULIT 22

(b) The following information is about two different alkalis.Maklumat di bawah adalah mengenai dua alkali yang berfainan.

Alkali Concentration Imol dm-3pHAlkali

Kepekatan Imol dm-3pH

Sodium hydroxide solution

0.113Larutan natrium hidroksida

Ammonia solution

0.110Larutan ammonia

Explain why the two alkalis have different pH values.Terangkan mengapa dua alkali tersebut mempunyai nilai pH yangberlainan.

[6marks]

(c) You are required to prepare dry barium sulphate salt.Anda dikehendaki menyediakan garam barium sulfat kering.

(i) Suggest two solutions to prepare barium sulphate salt.Cadangkan dua larutan untuk menyediakan garam barium sulfat.

(ii) Describe a laboratory experiment to prepare the salt. In yourdescription. include the chemical equation and ionic equation.Huraikan suatu eksperimen makmal untuk menyediakan garamtersebuLHuraian anda mest; mengandungi persamaan kimia danpersamaan ion.

[1 Om arks]

END OF QUESTION PAPERKERTAS SOALAN TAMA T

4541/2 © 2010 Hakcipta Jabatan Pelajaran Negeri JohorSULlT

~. to~

MARKING SCHEME OF CHEMISTRY TRIAL EXAMINATIONPAPER 2, 2010

MarkQuestion

Mark SchemeSubTotalmark

Mark

1. (a) (i)

Contact 11

(H)

Burn sulphur in air loxygen 11Heating of zinc sulphidel ZnS

(iii)

S03 11

(iv)

Concentrated sulphuric acid I11

(v)

Dissolve I Dilute in water 11

(vi)

Bubbles of gas are released 11 Beaker 11becomes warmll the mass of marble decreases

(b)

Ferum I Iron 11

(c) (i)

2NH3+H2S04-7(NH4)zS04Correct formula of reactants and product

1Balance equation

12

(li)

As fertilizers 11

I

Total10'---.

Mark

QuestionMark SchemeSubTotal

markMark

2.

(a) (i) Temperature at which a solid changes to11

liquid.(H)

83°C 11

(iii)

solid and liquid 11

(iv)

1. Heat energy absorbed 1

2. is used to overcome the forces of attraction

12

between the molecules I particles P.

4541/2 Answer © HAK CIPTA JPNJ 2010

1- (v)1. Water bath should be used and not ethanol1I

I

bath.I

III 2. Melting point of P is higher than boiling12 .I point of ethanol 178°C

II Ethanol isi I flammable.IIIi

(b) (i)Sublimation 11

Ii

(i i)1Iodine-131 1I

I!i

2. To treat thyroid patients II Diagnosis of12

Ithyroid Glands

II

Total10

Total(iii) I Oxygen gas I 1 I~iI 10 I

I MarkI

Question Mark SchemeI

SubITotalmark

IMark

3.

(a) (i) The negatively charged ionl particle 1I

1(ii)

OH-, CI-

I

1 1I(ii i)

Chlorine 11

(b) (i)

Carbon electrode Y 11

(i i)

2H+ + 2e -7 H2 11

(ii i)

1Insert a lighted wooden splinter into 1the test tube.

I2.A 'pop' sound is producel can be heard 12

I.(c) (i)

Hydroxide ion 11.(ii)Because hydroxide ion is located lower11

than chloride ion in electrochemical series.I

4541/2 Ans\\cr HAK C1PTA JPNJ 2010

4

MarkQuestion

IMark SchemeI SubTotal

markMark~I P:

Alkene 1

4. (a) (i) 11.

2.Q: Alkane 1I2

(ii)

I CnH 2n+2 I1I1I

(iH) ) Brown colour remains

I1I1

(iv)

I1I1I Acidified potassium manganate(VII) solution11Acidified potassium dichromate (VI) solution

(v)

Iln alkene carbon-carbon double bonds are)

1I

1Imore reactive than carbon-carbon single bonds.

(b) (i)

I Carbon dioxide

I

1I1

(ii)I C2H4

+ 302-7 2C02 + 2 H2O 11I1"

OR 2C2H6 + 702 -7 4C02 + 6 H2O(iii)

11. Compound Q produced mere soot.I

1

2. Compound Q has higher percentage of

I1I2carbon mass than compound P.

Total 10

MarkQuestion

Mark SchemeSubTotalmark

Mark

5. (a)

To allow movement of ions 11 To complete the11electric circuit

(b) (i)

Green colour solution turn to brown I yellow11

(H)

Fe 2+-7Fe 3++e 22


5

(iii)

11. A few drops of sodium hydroxide solutionlI1

ammonium hydroxide solution is added into the product formed around carbon Y.2. Brown precipitate is formed.

I1I2

[OR}1. A few drops of potassium

hexacyanoferrate (11) solution is added intothe product formed around carbon Y.2. Dark blue colour I precipitate produced.

(c) (i)

Purple solution is decolourised f turn I1I1colourless

(ii)

Act as oxidizing agent I1I1

.(iii)

Potassium manganate (VII) solution! Mn04-I1I1ioni~Efd.

j-. ..~A...,A,

o~,\.dj:'.

~

(d)I Bromine wat~r! chlorine watjZr! acidified

potassium dichromate (VI) solution

I1I1

Total 10

Mark


markMark

6. (a) (i)

Ethanoic acid! formic acid f any suitable dilute11acid.

(ii)

Because bacteria from air enter the latex and 11it produces lactic acid that causes the coagulation.

(iii)

Ammonia, NH3 solution 11

(b) (i)

Saponification ( Spelling must be correct) 11

(ii)

Concentrated potassium hydroxide, KOHl! 11

concentrated sodium hydroxide, NaOH.


6

(iii)To precipitate the soaps I to reduce the 11solubility of soap

(iv)

1. When a cloth with grease is dipped into 1soap, soap reduces the surface tension of water.2. The hydrophobic part dissolves in the

1grease 3. The hydrophilic part dissolve in water

1Max2

(c)

1. Agent Y s more effective 1

I

2. Detergent do not form scumllDetergent can still perform its cleaning

12

action in hard water 11 Detergent can still clean well in hard water.

Total

10


Question

7(a)

(b)(i)

7

Mark Scheme

Aluminium ion: 2.8Oxide ion: 2.8

1. Magnesium atom donates / releases 2electron to form magnesium ion / Mg2+

// Mg _ Mg2+ + 2e

Submark

11

1

Mark

TotalMark

2

2. Chlorine atom accepts / receives one I 1electron to form chloride ion / Cl'// Cl + e - cr

3. Magnesium ion and chloride ion are I 1attracted to one another by electrostaticforce.

2+

Chloride ion, cr magnesium ion, Mg2+

(ii)

1. Correct number of shells and number ofelectron

2. Correct charge

1

1 5


I8

1. Correct number of shell and electron 1

\

\

2. Correct number of atoms of elements I 1

3. Carbon atom contribute I needs I requires I 14 electrons to share

4. Chlorine atom contribute I needs I requires I 11 electron to share

5. One carbon atom share 4 valenceelectrons with 4 chlorine atoms.

1 5

(c)(i)! 1.Compound (b)(i) I MgCb is an ionic I1

compound2. In molten state, MgClz has freely moving I

1ions3. Compound (b)(ii) I CCI4 is a covalent I

1compound.4. CCI4 has no freely moving ions/l only I

1I

4consist of molecules.

(ii) 11. Ions in MgClz are held together by strong I1

electrostatic force2. A lot of heat energy is needed to overcome I

1the strong electrostatic force3. Molecules in CCl4 are held together by I

1weak intermolecular forces I van der Waals4. Less heat energy is needed to overcome I

1

I

4the forces

Total

4541/2 Answer © HAK CIPT A JPNJ 2010

20

9

Mark


markMark

8. (a)

Heat of combustion of ethanol is the heat 22

released when 1 mole of ethanol is burnt completely in air to produced 715 kJ.(b) (i)

Graph1. Correct axis and labels

1

2. Plot data

1

3. Straight line

13

(H)

The higher the number of carbon atoms per 11molecule of alcohol, the higher the magnitude of the heat of combustion.

(m)

1. [ 3200 - 3300 ] kJ mol -1 1

2. Dotted line in graph.

12

(c)

1. The heat of combustion of butanol is 1

higher than ethanol. 2. Butanol has higher number of carbon /

1

hydrogen atoms per molecule!/ The relative mass of butanol is higher thanethanol3. More carbon dioxide and water are formed.1

4. The combustion of butanol produced more

14

heat.(d) (i)

1. The energy level diagram shows 1

exothermic reaction! heat released to the surrounding.2. The energy level of reactants is higher

1

than the products 3. The heat of combustion released 715 kJ1

per 1 mole of ethanol 4. Ethanol burnt in oxygen to produced

14

carbon dioxide and water.

(ii)

1. Number of mole of ethanol = 6.9 = 0.15246

2. 0.15 mole will released 0.15 x 715 =

24

107.25 kJ ofheat

Total

-120

I

4541/2 Answer © HAK CIPT A JPNJ 2010

Question

9. (a)

10

Mark Scheme

1. Empirical formula is the formula thatshows the simplest ratio of atoms ofeach element in the compound.

Submark

1

Mark

TotalMark

\\\-\ \

2. Molecular formula is the formula that I 1shows the actual number of atoms ofeach element in the compound.

(b )(i)

3. Example: empirical formula of ethene' isCH2 and the molecular formula is C2H4

1 3

Element I Carbon

Percentage I 40.00

Hydrogen

6.66

Oxygen

53.33

Numberof moles

Ratio ofmoles

~~=3.331 6.~6 = 6.66

1 ! 2 1

1

1

(ii)

(c)(i)

(ii)

Empirical formula is CH20

n(CH20) = 18012n + 2n + 16n = 180

30n:: 180n=6

Because magnesium is more reactive than. hydrogen!! because magnesium oxide does! not react with hydrogen gas.

Lead oxide ! Stanum oxide I iron oxide !

copper-)i;)xide

1

1

1

1

1

3

2

1

1


11

(Hi) 1. Clean [5 - 15) cm magnesium ribbonwith sandpaper and coil it.

1

2. Weigh an empty crucible with its lid. I 1

3. Place the magnesium in the crucible and I 1weigh again

4. Record the reading. I 1

5. Heat the crucible very strongly. I 1

6. Open and close the lid very quickly. I 1

17. When burning is complete stop the

heating I

8. Let the crucible cool and then weigh it I 1again

9. The heating, cooling and weighingI process is repeated until a constant

mass is recorded.

1

Max 10

Description

Crucible + lid

Mass(g)

20

1

1

Total

Crucible + lid + Mg I Zn I Al

lI7~~,'b~le+ lid+ MgO I ZnO


12

Mark1

Question

I Mark Scheme[-SubiTotal

markIMark Ii~

10. (a) (i)I The higher the concentration of hydrochloric I

1I I

I

,tacid, the lower the pH value I vice versa(ii)

I 1. The pH value is actually a measure ofthe concentration of H+ ions [and OH- ionsJ !

1

2. The higher the number of H+ ion per unit

I1

volume of solution, the lower the pH value.(iii)

I Increasing acidity of hydrochloric acid is:I

1I

4p,

0,...~ Il..J

,V ,'-'

(b)11. Sodium hydroxide is a strong alkali. I1

2. Ammonia is a weak alkali

I1I

3. Sodium hydroxide ionises completely"in

I1

water to produce higher concentration of hydroxide ions,3. Whereas ammonia ionises partially in

I

1water to produce lower concentration of Ihydroxide ions.

4. The concentration ef hydroxide ions in

I1sodium hydroxide is higher than in ammonia solution.

5. When the concentration of hydroxide ion is I1

I

6higher, the pH value is higher 11pH of NaOH = 13 114 and pH of NH3 = 10 111

(c) (i)

I Barium nitratel Barium chlorideI

1

Sodium sulphatel Potassium sulphatel Any

1

suitable sulphate solution(ii)

I 1. Pour [20 - 100] cm3 of [0.1 - 1.0] mol\

1dm-3 barium nitrate solution into a beaker

II

I

2. Add slowly [20 - 100J cm3 of [0.1 - 1.0]1

mol dm-3 sodium sulphate solution into the beaker.~-~~-4541/2 Answer © HAK CIPTA JPNJ 2010

13

3. Stir the mixture. I1

4. Filter the mixture.

1

5. Rinse the residue with distilled water.

1

I 6. Dry the salt! crystals by pressing between

1two pieces of filter papers,

Chemical equation:Na2S04 + Ba(N03h ~ BaS04 + 2NaN03

I

1Note: If physical state is written, it must be

I '

Icorrect.

I Ionic eguation:Ba2+

+sol- ~ BaS04 I110-Total

II20


I

Percubaan Kimia Johor 2010 Kertas 2 With Answer

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