Stpm Percubaan 2008 Sabah Chemistry Paper 1

    CONFIDENTIAL*/SULIT* JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH   JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH   JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH   JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH PAPER 1 (KERTAS 1) JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH MULTIPLE-CHOICE (ANEKA PILIHAN) JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH One hour and forty-five minutes (Satu jam empat puluh lima minit) JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH JABATANPELAJARANSABAHJABATANPELAJARANSABAHJABATANPELAJARANSABAH

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EXCEL 2

CHEMISTRY (KIMIA)

)

)

JABATAN PELAJARAN SABAH UJIAN EXCEL 2 STPM Instructions to candidates: DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO. There are fifty questions in this paper. For each question, four suggested answers are given.   Choose one correct answer and indicate it on the multiple­choice answer sheet provided. Read the instructions on the multiple­choice answer sheet carefully. Answer all questions. Marks will not be deducted for wrong answers. Arahan kepada calon: JANGAN BUKA KERTAS SOALAN INI SEHINGGA ANDA DIBENARKAN  BERBUAT DEMIKIAN Ada   lima   puluh   soalan   dalam   kertas   ini.   Bagi   setiap   soalan,   empat   cadangan   jawapan   diberikan. Pilih satu jawapan yang betul dan tandakan jawapan itu pada helaian jawapan aneka   pilihan yang dibekalkan. Baca arahan pada helaian jawapan aneka pilihan itu dengan teliti.

2 Jawab semua soalan. Markah tidak akan ditolak bagi jawapan yang salah. ______________________________________________________________________________

This question paper consists of 15 printed pages and 1 blank pages. (Kertas soalan ini terdiri daripada 15 halaman bercetak dan 1 halaman kosong)

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CONFIDENTIAL*SULIT* Coordinator Datin Azizah Sektor Pengurusan Akademik JPN Sabah List of Contributors

No. Name 1. 2. 3. 4. 5. 6.

Yeo Peck Cheng Mokhtaruddin Harun Goh Siew Goik Nor Hanifah Jaraie Patricia Yahin Pang Kee Wen

School SMK Datuk Peter Mojuntin, PENAMPANG SMK Tamparuli,TAMPARULI SM La Salle, KOTA KINABALU SMK Maktab Sabah, KOTA KINABALU SMK Mat Salleh, RANAU SMK Maktab Sabah, KOTA KINABALU

3

Section A Four suggested answers labeled A, B, C, and D are given for each question. Choose one correct answer. 1

Ascorbic acid (vitamin C) cures scurvy and may help prevent the common cold. It is composed of 40.92% carbon, 4.58% hydrogen and 54.50% oxygen by mass. Determine its empirical formula. [relative atomic mass of C=12;H=1;O=16] A C3H4O3 B C2H3O2 C C4H5O4 D C8HO12

2

Calculate the relative atomic mass of naturally occurring Renium from the following data: Isotope Relative mass Relative abundance Renium-185 184.95 37.07 Renium-187 186.96 62.93 A B C D

3

4

185.02 185.72 186.21 187.03

Which of the following elements does not have a p electron that is paired ? Element Proton number A

Carbon

6

B

Oxygen

8

C

Neon

10

D

Magnesium

12

A small bubbles rises from the bottom of a lake, where the temperature and pressure are 8oC and 6.4 atm, to the water’s surface, where the temperature is 25oC and pressure is 1.0 atm. Calculate the final volume (in cm3) of the bubble if its initial volume was 2.1 cm3

4 A 0.35 B 12.7 C 14.0 D 42.0 5

What is the maximum number of emission lines possible for a hydrogen atoms with electronic energy levels of n=1, n=2 and n=3? A 1 B 2 C 3 D 4

6

The consecutive ionisation energies, in kJ/mol, of an element are as follows 940 (first), 2080, 3090, 4140, 7870, 16000, 19500 In which group of the periodic table is the element likely to occupy? A Group 13 B Group 14 C Group 15 D Group 16

7

The ionic radii of sodium, magnesium and aluminium are 0.098nm, 0.065nm and 0.045nm respectively. Which of the following statements explains the decrease in magnitude of ionic radii for the third period elements (Na to Al) The total number of electrons and the total number of protons in the nucleus increase The total number of electrons and the total number of protons in the nucleus B decrease The total number of electrons increase, whereas the total number of protons in C the nucleus remain constant The total number of electrons remains constant, whereas the total number of D protons in the nucleus increases. A

8

The table below shows the proton numbers of four elements represented by letters which are not the usual symbols for the elements concerned Element Proton number

W 3

X 11

Y 13

Z 19

5 Which element has the strongest metallic bond A W B X C Y 9

D Z What is the shape of the xenon tetraflouride, XeF4 molecule? A Tetrahedron B Square planar C Octahedron D Pyramidal

1 0

What is the pH of buffer solution that is prepared by dissolving 16.4 g of sodium ethanoate in 500 cm3 0.1 mol dm-3 ethanoic acid [Ka for CH3COOH = 1.8 x 10-5 mol dm-3] A 5.05 B 5.16 C 5.34 D 6.13

11 The partition coefficient of a substance P between ether and water 3is 8.0 at room temperature. An aqueous solution containing 5.0 g of P in 100 cm of water is extracted with 100 cm3 of ether. What is the maximum mass of P that can be extracted from the ether layer? A 0.35 g B 2.34 g C 3.98 g D 4.44 g 12 The equilibrium achieves when 20% of dinitrogen tetraoxide dissociates in a close container at the temperature T. If total pressure is Q, what is the equilibrium constant of the system? A B C

6 D

13 Stomach juices have a pH of 1.0 . Aspirin is a monobasic acid represented by HA (Ka = 10-4 mol dm-3) which dissociates into ions H+ and A- . What are the relative concentrations of H+ , A- and HA when aspirin from a tablet enters the stomach? A [H+] > [HA]>[A-] B

[HA]> [H+] = [A-]

C

[H+] >[A-]> [HA]

D

[H+] = [A-] >[HA]

14 Which of the following statements is correct about a reaction for which the equilibrium constant is independent of temperature? A

The rate constant do not vary with temperature.

B

There are equal numbers of moles of reactants and products.

C

The enthalpy change is zero

D

The forward and reverse reactions are of the same order.

15 The pKb value for aqueous ammonia at 25oC is 4.8 . What is the correct pKa value for the ammonium ion at this temperature? A

4.8

B

2.2

C

9.2

D

9.6

16 The solubility product of silver chloride is 1.0 x 10 -3 mol2 dm-6. How many moles of silver chloride will dissolve in 1 dm3 of a solution of sodium chloride of concentration 0.10 mol dm-3? A

1.0 x 10-14 mol

B

1.0 x 10-16 mol

C

1.0 x 10-9 mol

D

1.0 x 10-5 mol

7

17

18

19

Which of the following is always true for an endothermic reaction? A

The reaction can take place at room conditions

B

The rate of reaction at room conditions is slow

C

The reaction is reversible

D

Heat is absorbed from the surroundings

In the transformation of compound X to compound Z, it is discovered that it involves compound Y. The stages involved are, X→Y ∆Hθ = positive Y→Z ∆Hθ = negative Which of the following profiles is appropriate with the data above?

A

C

B

D

An element X liberates hydrogen from dilute hydrochloric acid as well as from aqueous sodium hydroxide. X could be A Aluminium B Lead C Sulphur D Carbon

8

20 Calcium chloride is soluble in water whereas calcium fluoride is not because A

calcium fluoride is a covalent compound

B

the lattice energy of calcium fluoride is very high

C

fluorine is more reactive than chlorine

D

the charge density of the Ca2+ in CaF2 is higher than in CaCl2

20 Calcium chloride is soluble in water whereas calcium fluoride is not because A

calcium fluoride is a covalent compound

B

the lattice energy of calcium fluoride is very high

C

fluorine is more reactive than chlorine.

D

the charge density of the Ca2+ in CaF2 is higher than in CaCl2

21 Which of the following changes occurs on descending Group 14? A

The +2 oxides become more stable.

B

The +4 oxides become more stable.

C

The oxides become more amphoteric.

D

The tetrachlorides become very stable.

22 Silicon (IV) oxide is a solid whereas carbon (IV) oxide is a gas. This is because A

Carbon is more electronegative than silicon

B

Silicon(IV) oxide partially ionic whereas carbon(IV) oxide is purely covalent

C

The silicon-oxygen bond is stronger than the carbon-oxygen bond Silicon (IV) oxide is a giant molecule whereas carbon (IV) oxide is a simple molecule.

D

23 In which of the following species does nitrogen exhibit the highest oxidation state A

NH3

B

N2O5

9 C

HNO3

D

N2H4

24 In industry, nitric acid is obtained from ammonia by which of the following processes? Hydrolysis A B

Condensation

C

Catalytic oxidation

D

Hydrogenation

25 Which one of the following explains why the volatility of group 17 elements (chlorine to iodine) of the Periodic Table decreases on descending the group? The enthalpy of vapourisation decrease A B

The melting and boiling points increase

C

The number of electrons increase

D

The strength of intermolecular forces increase.

26 Which is the correct definition of a transition element?

27

A

An element with incompletely filled d-sub-shells.

B

An element that exhibits variable oxidation states.

C

An element that forms ions with incompletely filled d-sub-shells.

D

An element that forms coloured complexes.

What is the number of faradays needed to produce 24 cm3 of gas at the anode during the electrolysis of dilute sulphuric acid? [1 mole of gas occupies 22.4 dm3 at s.t.p] A 0.01 F B 0.02 F C 0.03 F D 0.04 F

2 8

Among the following, which is the strongest acid? A

CH3NH2

10 B

CH3CH2NH2

C

NH3

D

C6H5NH2

2 9 A B

Cl–

C

•CHCl3

D

•CH2Cl

30

A

Which of the following statements concerning the alkenes, X and Y are correct? CH3CH2CH = CH2 and CH3CH = CHCH2 X Y Both X and Y show cis-trans isomerism.

B

Both X and Y have the same boiling point.

C

Both X and Y react with bromine to form 1, 2-dibromobutane.

D

Under suitable conditions, X and Y react to form a polymer.

31

3 2

Which of the following is an intermediate in the reaction between methane and chlorine in the presence of light? CH3 +

When P (a gas) reacts with Q, a mixture of CH2BrCH2Br and CH2BrCH2OH are produced. P and Q are probably P Q A

ethene

B

ethene

bromine water sodium bromide solution

C

HBr(g)

ethene

D

Br2 vapour

ethene

Which of the following would react with 2,4-dinitrophenylhydrazine as well as alkaline iodine? A

CH3CHO

B

CH3COCH3

11 C D

3 3 A

34

COCH3 CH3CH2CHO

All the following reagents can be used to distinguished propanone from propan-1-ol except Iodine and aqueous sodium hydroxide

B

Tollen’s reagent

C

Acidified potassium manganate(VII)

D

2,4-dinitrophenylhydrazine

The cleavage of the C-O bond in ethanol involves specific reagents and reaction conditions. Which of the following reagents and reaction conditions is true of the reaction? K2Cr2O7/H+, heat A B

Sodium metal, room temperature

C

Concentrated H2SO4 (excess), heat

D

CH3COOH, concentrated H2SO4, reflux

35 Which of the following reaction produces ethanol? A

Ethyl ethanoate and lithium tetrahydridaluminate

B

Methyl ethanoate and hot concentrated sulphuric acid

C

Ethane and dilute aqueous potassium manganate(VII) solution

D

Chloroethane and ethanolic sodium hydroxide solution

36 Which of the following statement is not true about 2-iodo-2-butene? A

All the carbon atoms are planar

B

It will decolourise bromine in CCl4

C

It is stabilized by the delocalized pi electron system

D

It has a higher boiling point then 2-chloro-2-butene

12

37 An organic compound Q reacts with hydrogen cyanide to produce a compound which on hydrolysis with dilute hydrochloric acid produces a compound with the structural formula of H |

R −C−COOH |

H To what class of compound does Q belong to? Aldehyde A B

Ketone

C

Carboxylic acid

D

Ester

38 Which of the following compounds could be the product of a reaction involving a nucleophilic attack by cyanide ions in aqueous ethanolic solution? CH2 = CHCN A

3 9

B

(CH3)2CHCN

C

C6H5CN

D

CH3CONH2

GABA is a neuro-transmitter released by red algae which encourages shellfish larvae to settle on the ocean bed GABA has the structural formula as shown below H2NCH2CH2COOH In what way does GABA differ from amino acid obtained by the hydrolysis of protein? It does not form a zwitterion A B

It is not soluble in water

C

It is not a 2-aminocarboxylic acid

13 D 4 0

It does not form a polyamide linkage.

Which of the following pairs of monomers could undergo condensation polymerisation? CH3CH=CH2 and HOCH2CH2OH A B

ClCO(CH2)COCl and H2N(CH2)4NH2

C

CH3COOH and C2H5OH

D

CH2=CH(CH3)CH=CH2 and CH2=CHCl Section B

For each of the questions in this section one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct. The responses A to D should be selected on the basis of the following. A 1 only is correct

B 1 and 2 are correct

C 2 and 3 only are correct.

D 1 , 2, and 3 are correct.

41 Which of the following statements are correct? 1 2 3

In crystalline solids, particles are held rigidly together by strong attractive forces in a three dimensional orderly structure called the lattice structure In amorphous solids the particles are not arranged in an orderly fashion All solids are denser than liquids

42 Which of the following species do not have a tetrahedral shape? 1

PH4+

2

ICl4–

3

XeF4

43 Which of the following statements are true for hydrogen bonding? 1

It is cause for the high melting of water

2

It is responsible for ice being less dense than water

3

It is responsible for the high enthalpy of vapourisation of water

14

A 1 only is correct

B 1 and 2 are correct

C 2 and 3 only are correct.

D 1 , 2, and 3 are correct.

44 The diagram below shows the vapour pressure-composition graph for the ideal mixture of benzene and toluene at 20oC.

Which of the following statements is true of a mixture which contains 40 % of benzene at 20oC? 1 The partial vapour pressure of benzene is 4.0 kPa

45

2

The partial vapour pressure of toluene is 1.8 kPa

3

The partial vapour pressure of the mixture of benzene and toluene is 13 kPa

The e.m.f of the cell Pt(s) / H2(g) , H+(aq) // Zn2+ (aq) / Zn (s) depends on the 1 pressure of the hydrogen gas.

15

46

2

concentration of the H+ ions.

3

concentration of the Zn2+ ions

Which of the following statements about PbCl4 are correct? 1

Its molecule is tetrahedral in shape

2

It is a liquid at room temperature It readily decomposes to Pb and Cl2 on heating

3

A 1 only is correct 47

2 3

50

D 1 , 2, and 3 are correct.

Formation of a blue precipitate when ammonia gas is bubbled though aqueous copper(II) sulphate Reaction of ammonia gas with excess chlorine to form nitrogen trichloride Formation of a dark blue solution when excess aqueous ammonia is added to solid copper(II) hydroxide

Malic acid, HOOCCH(OH)CH2COOH is found in apples. Which of the following is true about malic acid? 1

It has one chiral centre

2

It has a secondary alcohol It form esters with ethanoic acid or with ethanol

3 49

C 2 and 3 only are correct.

In which of the following reactions does ammonia react as a base? 1

48

B 1 and 2 are correct

Ethyl butanoate is used as an artificial pineapple flavoring. Which of the following pairs can be used to produce the ester? 1

CH3CH2CH2COOH and CH3CH2OH

2

CH3CH2CH2COCl and CH3CH2OH

3

CH3CH2COOH and CH3CH2CH2OH

Which of the following react with both phenylamine and aminocyclohexane?

16 1

Ethanoyl chloride

2

Bromine water

3

Sodium hydroxide

END OF QUESTION PAPER