Stpm Trial 2009 Che Q&a (johor)

, papercollection

JABATAN PELAJARAN JOHOR JA I JOHOR JABATA N PELAJARAN JOHOR JABATAN JAl JRAN JOHOR JA IJOHOfi IN JA l 96211 jRAN JOHORJA IJOHOf, PERCUBAAN STPM 2009 IN JABATAN PELAJARAN JOHOR JA IJOHOR JABATAN PELAJARAN JOHOR JABATAN I JOHOR JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN JOHOR JA IJOHOR JABATA N PELAJARAN JOHOR JABATA N JABATAN PELAJARAN JOHOR JA JABATANPELAJARANr ---- - - - . . -- - . - . . . - -- - - -BATA N PELAJA RA N JOHORJABATAN JABATA N PELAJARA N J CHEMISTRY (KIMIA) BATAN PELAJARAN JOHOR JABATA N BATAN PELAJARAN JOHOR JABA TAN JABATAN PELAJARA N J JABATAN PEUJARAN JOHOP 1.1 D A,A"" DIn TA D ,.11. 1 rnU/lR JABATA N PELAJARAN JOHORJABATA N JABATA N PELAJARAN JOHOJ PAPER 1 (KERTAS 1) 'R JABATAN PELAJARAN JOHOR JABATA N JABA TAN PELAJA RA N JOHOA JnOM m. r "~Jn~" Jvu ciR JABATAN PELAJARAN JOHOR JABATAN . PELAJARAN JOHOR JABATA N JABATAN PELAJARAN MULTIPLE-CHOICE (ANEKA PILIHAN) JABATA N PELAJARA N . PELAJA RA N JOHOR JABATA N JABATAN PF.f.A.JARAN.I()H()R .JARATAN PF.1A.JA RAN .f()H()R.lA RATA N PF.f.A.JARA N JOHOR JABATAN JABATAA One hour and forty-five minutes (Satu jam empat puluh lima mlnit) IOHOR JABA,TAN JABATAfI _ __. ________ . __ ___ _• __ ._. __ . __ . __...... __. __ .. _ ___ .. _ .. _.... _ __.....__... JOHORJABATAN JABATAN PELAJARAN JOHOR JA BA TAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATA N ,j

.JABATAN PELA.JARAN .JOHOR

SI.JIL TINGGI PERSEKOLAHAN MALAYSIA Instructions to candidates: DO NOT OPEN TIllS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO.

There are rthy questions in this paper. For each question, four suggested answers are given. Choose Doe correct answer and indicate it on the multiple-choice answer sheet provided. Read all instructions on the multiple-choice answer sheet very carefully.

Answer aU questions. Maries will not be deducted/or wrong answers.

This question paper con.i... of 3.1 printed pages.

STPM962/1

*This question paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL"

»

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2

CONFIDENTIAL"

Section A Four suggested answers labelled A, B, C and 0

correct answer. 1.

are given for each question. Choose one .

Which of the following sketches show part of the mass spectrum of the refrigerant,

CF2CI 2? [The isotopes are : 12C ,

11 (,

18F t M et

31CO

I

c

A

mle J'IIlio

120

122

[24

120

122

124

B

mk:

' - - ' - - - ' - - - ' - - - . mle ratio 120

2.

122

120

124

122

"no

124

The unit cell of a metal M is shown below. Given the volume of the unit cell is V, cm 3 and

the volume of 1 mol of M atoms is V 2 cm 3 • What is the value of the Avogadro constant?

g. (,

'f

-:i

./' ..

';5 j

• .

.....

e n' h. . o t-

../

.....

,

(J'~ ..

../

A.

V,/V,

c.

01,/ V,) x 7

•

/' 01,/V,)x4

c.

01, / V,) x 14

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CONFIDENTIAL'

4

Antimony Sb, is in Group 15 of the Periodic Table. The ion below has a square-based

3.

I

pyramidal shape.

He

1-1 ; l\

Be

60 Co N;o.Fl

.-

F

,~J~F

Ne

F~~

Deduce the total number of electrons around the antimony atom and the value of n?

Total number of elec;trons

)(

\/

n(n-t) -\\ 0 ((I - I) ~'). . (\-+ \

4.

value of "

10

1

10

2

12

1

12

2

Gaseous particle X has a proton number n and a charge of +1 . Gaseous particle Y has a

proton number of (0+1) and is isoelectronic with X. VVhich statement correctly describes X and

Y?

0)

X has a larger radius than Y X requires more energy than Y when the second electron is removed f

B

from each particle ~

c

X releases more energy than Y when an electron is added to each particle

0

X and Y belong to the same group in the Periodic Table

o

6.

6,-11

H

Y

'"

(J

HLC~LH I H

VVhich of the following correctly describes the approximate values of the bond angles in

the molecule above? y

(J

1800

90"

B

90" 105'

160'

90"

.tZJ

120'

105'

109'

0

120'

109'

109'

6

A

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CONFIDENTIAL' , 6.

In which pair of mo~utes is the permanent dipole in molecule I greater than that in

molecule II? II

I

CI

CI

"

CI

"I C= C'\ /'

C=C/' /' '\

CH,

CH,

CH,

CI

CH,

CH,CHCI,

B

H CI

HC. C H Ii ~I CI

~CI

C CI

D

CI

~

CI 7.

CI

~ CI

The rate equation for the decomposition of hydrogen bromide 2HBr(g) ~ H, (g) + Br,(g)

is : Rate = k[HBr)' Which of the following conclusions can be drawn from this information? '" A

The value of k depends on the concentration of HBr.

®

The rate of appearance of Br2 is half the rate of disappearance of HBr.

\( C

Doubling the concentration of HBr will double the rate of reaction.

o

The presence of a suitable catalyst will increase the value of k.

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CONFIDENTIAL',

8

------ y / /' - - - --x

8.

In the diagram above, curve

X was obtained by observing the decomposition of 100 em3 of

1.0 mol dm" hydrogen peroxide, catalysed by manganese (IV) oxide.

Which alteration to the original experimental condition would produce curve Y? A

® 9.

Adding water Adding some 0.1 mol dm" hydrogen peroxide

C

Using less manganese(lV) oxide

D

Lowering the temperature

The graph below shows the variation of pH value with volume of base added in an acid·

base titration .

,. 13 12 11 10

• 8

pH

7 6

, • J

2

1

.L-_ _-----~--Volume of base addcdIcm 3 Which of the following statements is not true about the mration above? '" A

The acid and base used in the titration may probably be ethanoic acid and sodium hydroxide respectively.

v

B

The pK. of the acid used is equal to 4.7.

C

The sa~ formed in the titration undergoes hydrolysis to produce OH'

®

ions. A suitable indicator for the above titration is methyl orange',

, -

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CONFIDENTIAL' 10.

The pH of a 1.0 mol dm-3 solution of a weak monobasic acid is 5. What is the

dissociation constant of the weak acid?

11 .

A

1.0 x llr mol dm"

B

1.0 x 10-' mol dm"

@

1.0 x 10. , 0 mol dm,3

o

1.0 x 10". mol dm-3

Hydrogen sulphide reacts with water according to the following equation . [,

' ._

"vI

(

I

~

iJ

2H,O' (aq) + 5'- (aq)

H,5 (aq) + 2H,O (aq)

Which of the following aqueous solutions when added would cause the system at

equilibrium to shift to the left? < •

A

Ammonium chloride

B

Sodium carbo~ate

C

Sodium ethanoate .

@

Ammonia

-''·:T ...

~

..". : 12.

When the system CI,(g) + PCI,(g)

........ PCI,(g) is in equilibrium at 600'C, at 1

atm pressure, the value of the equilibrium constant , Kp is 30.

VVhat is the valUe of ~ at a pressure of 2 atm at the same temperature?

.S:.

A

®

20

30

C.

60

D

100

\

13.

A solute, S exists in the same molecular state when dissolved in ether and water.

When the two solutions are in equilibrium, the concentration of solute S in ether solution is 6 times higher than that of the aqueous solution. A solution containing 14.0 9 of 5 in 240 em' of water is extracted with 40 cm 3 of ether. Calculate the total mass of S extracted from water.

A

2.0g

B

6.0g ,

©

7.0g

D

8.0 9

'J 8,.6 c ' '(

'+O ~

2'10 I~. 'I(

,

fif?'

>I =

I;! \3

>(

,~ " lL

Ilx - 14 ·3>" it

l(

"

{

b

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a mixture of

cell to the electrode in the in the Fe3+/ Fe2+ cell will increase

---

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14

CONFIDENTIAL" 16.

In the construction of cardiac pacemakers, it is possible to use a very small magnesium ,

electrode which creates an electrical cell with the inhaled oxygen. The relevant half-cells are

MS + (), -+ H~

as follows. Mg"+

2e~ Mg

--r fV1g" .. t--l :z.O E6 =-2.38V

%02 + 2H+ + 2e ~ H~ Under standard conditions, the cell

3.25 < Et _

p

~

EO = +1.23 V (.«~

a.m.t would be 3.61

.3!ln F

[ p' J I ] - IC. r e CI ': t . . -.I

V , but in the body a potential of 3.25 V

is more usual. What is the best explanation of this lower a.m.f?

A

The small size of the magnesium efectrode

B

The low concentration of Mg2+ ions surrounding the magnesium electrode

C

The high resistance of the body fluids surrounding the electrodes.

@) 17.

The pH belween 7 and 8 of the body fluid surrounding the electrodes.

The enthalpy change for two reactions are given by the following equations.

2Fe(s) +

'I, O,(g)

~ Fe,O,(s);

C(s) + % O,(g) ~ CO(g) ;

mor' -110 kJ mor'

dH = - 822 kJ dH =

What is the enthalpy change for the following reaction? 3C(s) + Fe,O,(s) ~ 2Fe(s) + 3CO(g)

o

18.

-.2:>.

A

+712 kJ m01 -'

®

+492 kJ m01·'

C

- 492 kJ mor'

D

-712 kJ mor'

3{-lIo)

Which value would be required to estimate the lattice energy for the hypothetical ionic

compound. MgH?

®

The electron affinity of hydrogen

B

The first ionisation energy of hydrogen

C

The magnesium-hydrogen bond energy

o

The standard enthalpy change of formation of MgH z

x+ \

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,

c., 1-\ I .. I 0,CONFIDENTIAL' 19.

_~) ~CO"L

...

~ H.O

16

.;;.

4.0 9 of a hydrocarbon required 16.0 9 of oxygen for complete combustion and 9.0 9 of

water was produced in the reaction. What was the mass of carbon dioxide produced? [Relative atomic mass of 0=16, C=12, H=lJ

A

@ 20.

Ug

B

Mg

11 .0 9

0

22.0 9

The values of p~ of several substance are given below.

pI<"

Substance

NH,

4.75

CH,NH,

3.36

CH 3CH2 NH2

3.27

CeHsNH2

9.38

Which of the following is the strongest acid?

21.

A

NH/

C

CH,CH, NH,·

B

®

Consider the sequence of oxides given below. Which series shows an increasing order

of melting point?

22.

A

Ci,O" Ai,O" SO" SiO,

S

S03. el 20 r • Al 20]. Si0 2

®

SO" Ci,o" SiO" Ai, O,

o

SiO" Ai,O" CI,o" SO,

The process of chemical etching consists of partially dissolving a metal in a suita~e

solvent. By careful masking of the metal, it is possible to produce a pattern in or on the metal. Which of the following aqueous solutions could be used to etch a pattern in aluminium? A

Ethanoic acid

B

Dilute nitric acid

@) 0

Sodium hydroxide

Ht

NO,-

No' OH-

Concentrated nitric acid

, !

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CONFIDENTIAL' 23.

Which of the following statements regarding lead(lV) oxide is not true? - A

It is amphoteric

.., 8

It easily decomposes when heated

C

@ 24.

It has ionic bonding with covalent characteristics.

It is formed by heating strongly lead(lI) oxide in oxygen

Which reaction of ammonia does not involve the non·bonding pair of electrons on the

nitrogen atom? A

NH,(g) + CH,I(g) _

CH,NH; r (s)

B

NH,(g) + HCI(g) _

NH,CI(s)

C

2NH,(I) + 2Na(s) _

® 25.

2NH,(aq) + Ag'(aq) _

2NaNH,(s) + H,(g) [Ag(NH,)'J'(aq)

p. Q, and R are three elements in Group 17. a is a solid at room temperature. P- ion is

the weakest reducing agent among P-,

a- and R- .

What is the arrangement of the elements in increasing intensity of colour?

® B C D

26.

P. R.Q R. Q, P P,Q, R Q,R, P

,''..

A

""

i:

Which of the following complexes does not exhibit optical isomerism? A

[Cr(C,O,),(H,O),f

B

[Cr(C,O,J,]>-

C

[Co(en),CI~

,\ )

® 27.

-... ' /

( /Y~

[Co(NH,J,(NO,),]

,

The intermediate species formed in the mechanism of the reaction between methane

and chlorine in the presence of light is ACH;

..

Bcr

C CHCI,

II

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bCCxH~ 2. '5

CONFIDENTIAL·

CH,

-t .

1

o~

---7 2M) CO, -r30o{-i.,O

0, 20

,06 COL

--t

+

O.OQ~'>

28.

I ':.

I' .., o. () 1«; I

When 60 em3 of a hydrocarbon were burnt completely in oxygen, 240 em 3 of carbon

dioxide and 0.0125 mol of water were produced. What is the molecular formula of the hydrocarbon? (The volumes of aI/ gases were measured at room conditions. The molar volume of any gas at room conditions is 24.0 dm3)

29.

\..I

U

A

C2He

B

C3Ha

C

C3He

®

C4 H10

I

Ole - c.oo " NH.

Which type of isomerism is shown by each of the following organic compounds?

p.

,c.

CJ,;

.,;

C.

(Y; llA

XB

o D

""'ok

;.~ ~; o-se

30.

Which one of the following compounds has the highest PI<. value?

A

@-NH,

C

CH,-N-CH,

B @ -CH2NH,

®

I

O'N-@-NH,

CH, 31 .

Lactic acid can be formed from ethanol as shown in the reaction scheme below. OH *pI

OI,CH,OH -

*'PO

OI,CHO --;;0;- Q

step m

01, -

f" - I

C=0

OH

, Name the types of reaction that occur in step , I and step III. Step I

Step III


Oxidation

Hydrolysis

B

Reduction

Esterification

C

Condensation

Oxidation

0

Dehydration

Condensation

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CONFIDENTIAL· 32.

Which of the following compound is formed when ethanoy1 chloride is reacted with

,?

O-I{_ -q H,N --
-

A

H'N ~CH'OCOCH' OH

@ . CH,COHN --(c))--CH, OCOCH, ' oCOCH, 33.

The structure of cyclohexanone is shown below.

c Which statement is true about cyclohexanone?

A

It is an aromatic ketone.

B

tts molecular formula is CSH120 .

C

It can be oxidised td benzoic acid.

® 34.

It will give a precipitate With 2,4-dinitrophenylhydrazine.

Natural rubber is a polymer made up of isoprene units with the structural formula

CH, = C(CH,)CH = CH, . Which of the following is not true about this statement? A

The IUPAC name for isoprene is 2-methylbuta-1 ,3-diene

B

Natural rubber is made from unsaturated molecules

C

Natural rubber becomes hard when vulcanized

@

Natural rubber is a mixture of cis polymers and trans polymers

-

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CONFIDENTIAL"

c

35.

,

X, Y and Z.are three different compounds. X reacts with sodium to give off hydrogen

gas. X and Y react to form an ester. X and Z also react to fonn the same ester but at a much slower rate. Compound Y is probably

co, b 'Ej ol:. ol·ci

I"" rel="nofollow"> rorc(l'1(j~ I

A

propan-1-01

y

B

propana l

~ i'f0p"no: L

© D 3&.

X

propanoic acid propanoyl chloride

Which of the following statements is incorrect regarding the compoundge'ow?

eLI

CH, (OH)CHCH,COCH,

,.- 1 -

A

It will decolourise acidified potassium manganate(VII).

B

It can react with alkaline iodine to give a yellow precipitate.

C

It is optically active.

® 37,

~ II ' ell -CH,. C-C.I-I _ I

•

OH

It will produce a brick-red precipttate with Fehling's solution.

When X (a gas) reacts with Y, a mixture of CH,BrCH,Br and CH,BrCH,OH are

produced. X and Yare probably

38.

X

Y

®

Ethene

Bromine water

B

Ethene

Sodium bromide solution

C

HBr(g)

Ethene

D

Br2vapour

Ethene

Q. ~

al
A compound Q has the following composition by mass. Carbon, 64.3%; hydrogen,

7.1%; oxygen, 28.6%. Q reduces Fehling's solution to copper(l) oxide. 0.1 mol Q reacts with 4480 em' hydrogen gas at s.t.p. with nickel as catalyst. Q is [Relative atomic mass: H, 1; C, 12; 0 , 16. 1 mol gas occupies 22.4 dm' at s.t.p.]

@

CH, = CHCHO

C

CH,CH = CHCH = CHCHO

B

CH" CCH,OH

D

CH,COCH = CHCH = CHOH

0

C

H

5.~58

I .I '+

0 ITiS8 \ ". J

c,I-I.O

C, H%O,

/1

C3 H. O H.

*v·2

~

(-H

c, H, 0

D

...,

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26

CONFIDENTIAL' 39.

An organic compound, W, is boiled with aqueous sodium hydroxide and the reaction

mixture is allowed to cool. Upon cooling , compound X and compound Y (an alcohol) are

produced. On acidification, compound X is converted to compound Z (C 3Hs0 2) . Compound Y gives a positive triiodomethane (iodofonn) test. Compound W is likely to have the structural

formula

A

CH,CH,COOCH,

B

CH,COOCH,

® D

40.

CH,CH,COOCH,CH, CH,CH(OH)CH,COCI

Which of the following pairs of reactants will not produce the compound with the

structural fonnula shown below.

,

CH, @-f-cH,CH, c

A

OH

CH,CH,MgBr

and

@-e0CH,

and

@-MgBr

CH, B C

I

CH,CH,-G=O @-COCH,CH, and

CH,MgBr

,

~

@-cH,CH,MgBr

a~d

CH,CHO

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CONFIDENTIAL'

Section B

For each question in this section, one or more of the three numbered statements 1 to 3 may be COI1>lCf. The responses A to 0 should be selected as follows: A

B

C

0

1 only

1 and 2 only

2 and 3 only

1,2and3

is correct

are correct

are correct

are correct

41 The energy-level diagram for a hydrogen atom shows several electronic transitions with frequencies f. and 's.

'1. '2. ().

n=_ n~4

,,=3

j.

n=2

f,

. f,

f,

n= 1

Which of the following statements is/are true of the above diagram?

v

cD

f. and '5 represent lines in the Balmer series.

® ®

The lines represented by f, .'2 and'3 are non-visible.

'3 can be used to calculate the ionisation energy of hydrogen. r{.Gltk

42.

@ 1-\

43.

a L.

d,

~1:'" ~o ((

Which of the following mixtures would produce a solution of pH greater than 7. 25 em' of 1.0 mol dm-' NaOH(aq) and 25 em' of 1.0 mol dm-' CH,COOH(aq).

2

25 em' of 1.0 mol dm-' NH,CI(aq) and 25 em' of 1.0 mol dm-' NH,(aq).

3.

25 em' of 1.0 mol dm'" NaOH and 25 em' of 1.0 mol dm'" CH,COONa.

Which of the following can be determined by using a mass spectrometer?

CD

D @

,(9

The relative molecular mass of an organic compound The accurate mass of a nuclide (isotope) The proton number of an unidentified element

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CONFIDENTIAL"

30

A

B

C

0

1 only

1 and 2 only

2 and 3 only

1, 2 and 3

is correct

are correct

are correct

are correct

A cell is reDresented by the cell diagram below. qoi

<:c,-l.

Cr(s) U C"'-(aq) II Fe"(aq), Fe'-(aq) I Pt(s)

Which of the following will increase the e.m.f of the cell?

45.

1

I~ase the concentration of C,...

(,

<2)

Decrease the concentration of Fe2+

fr " . ..; .

@r

Increase the concentration of Fe'·

I ...

- -> ( . ,"' .1) .. .

- ,l I

I:: ,'<0 ~

n ______.' __ _ ) { { I Gi..'1II:

The element X has a proton number of 25. Which of the following statements islare

true of X?

D

46.

47.

[)

The metal X has a high density

®

X forms coloured complex ions

®

The highest oxidation number of X in its ion is "7

Which of the following element(s) haslhave the above arrangement of atoms in its

Gl

diamond

~

silicon

3.

boron

Which of tile following reagents react(s) with both benzene and methylbenzene?

(1J (\

Chlorine gas in the presence of anhydrous aluminium chloride

2

Concentrated sulphuric acid on reflux

3

Acidified potassium manganate(VlI) on reflux

J ~-

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CONFIDENTIAL"

A

B

C

D

1 only

1 and 2 only

2 and 3 only

1, 2 and 3

is correct

are correct

are correct

are correct

48.

CH2=CH-@- CH, Br

What type(s)'of reaction would the above compound undergo?

(i)

IlCiJ 6) 49.

Nucleophilic substitution Electrophilic addijion

Free radical substitution

A compound P decolourise bromine water and does not form a white precipitate with

ethanolic silver nitrate solution. Compound P is

,

(jJ

<2<-CH=CH, CI

" 2. 3,

@-CH,CH,CI CH, =CHCH,CI

CHPH HO--@-+-CO:;H OH 50.

Which of the following statements is/are true regarding the compound above?

It can fOfTl'l condensation homopolymer.

B

It can rotate the plane of plane-polarised light.

3.

1 mol of the compound would react with sodium to produce 2 moles of hydrogen gas.

-

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JABATAN PELAJARAN JOHORJA n ,~'" n r , , " n "IJOHORJABATAN PELAJARAN JOHORJABATAN JABATAN PF.TA.T4RAN JOHOR JA I JOHOR .TARATAN PF.T A.TARAN.TnHnR .TARAT4N JAl 962/2 4RAN JOHOR JA I JOHOfi PERCUBAAN STPM 2009 IN JAt. ...... • ~~.ovARAN JOHOR.JA I JOHOJ. .... ~. .. . .... ~~.ov ~ v ~ ~ ~ .JN JABATAN PELAJARAN JOHOR JA I JOHOR JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN JOHOR JA I JOHOR JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN JOHOR JAD" uiJ> r CL.IiJlil\/1l.[ JOHOR JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN JO}H)D TAJUrA~ ! pn A !ADAM Tnur)D JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN J01 CHEMISTRY (KIMIA) JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN J01,Vl\ ,,,,,,,,unJ/',, , ......nJnJV1" J V 1 H " , .JABATAN PELA.JARAN.JOHOR JABATAN JABATAN PELAJARAN .JOHC PAPER 2 (KERTAS 2) 'JR .JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN JOHC 'JR JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN.JOHOR JABATAN PELA.JARANJOHOR .JABATAN PELAJARAN JOHOR JABATAN .JABATAN PEL,. Two hours and thirty minutes (Dua jam tiga puluh minit) ?AN JOHOR JABATAN JABATAN PEL_____ __ . _ ____ __ ____ . _____ _ ____ _____ __ . _ _ __ _ __ ____ __ ___ _ __ __ ___?AN JOHOR JABATAN JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN ...

,.

•• ,

••

. . ... .

...

JABATAN PELAJARAN JOHOR

SI.JIL TINGGI PERSEKOLAHAN MALAYSIA

Instructions to candidates:

Answer all the questions in Section A in the spaces provided. All working must be shown. For numerical answers, unit must be quoted wherever they are appropriate. Answer any four questions from section B. For this section, write your answers on the answer sheets. Begin each answer on a fresh sheet ofpaper and arrange your answers in numerical order. Tie your answer sheets to this booklet.

For Examiner's use (Untuk kegunaan pemeriksa) 1 2

3 4

5

6

Answers may be written in either English or Malay. A Data Booklet is provided.

7

8 9 10

Total (Jumlah)

This question paper consists of 3~ printed pages.

STPM96212 *TIris question paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL·

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Section A [ 40 marl<s) Answer all the questions in this section.

1. (a) Iodine, 12, crystallizes in a face-centred cubic lattice. (i) Draw a unit cell for the iodine crystal lattice .

[1 mark]

(ii) Calculate the number of iodine atoms in one unit cell.

[1 mark]

(b) The triple point of carbon dioxide is at -57°C and 5 kPa, while its critical paint is at 31°C and 73 kPa. (i) Define triple point.

[1 mark]

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(ii) Sketch the phase diagram of carbon dioxide based on the information above.

[3 marks]

(iii) Based on your diagram in b(ii) , explain why solid carbon dioxide sublimes at

room temperature.

[1 mark]

(iv) A piece of solid carbon dioxide with a mass of 5.50 g is placed in a 10.0 dm3 vessel that already contains air at 93.7 kPa and 24.0oC . After the carbon dioxide has totally vaporized, calculate the total pressure in the container at 24.0oC. [3 marks]

- - - - - -- - -- - - - - -

- - -- - - - - -- - -

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2. Consider the incomplete Born-Haber cycle and the table of data below.

I

...................................................... ,

. ....................................................

, Standard enthalpy change

Value of enthalpy change/kJmor1

Enthalpy of atomization of chlorine

+121

Enthalpy of atomization of calcium

+178

First ionization energy of calcium

+590

Second ionization energy of calcium

+1145

Electron affinity of chlorine

-364

Lattice energy of calcium chloride

-2237

(a) Complete the Born-Haber cycle above by writing the appropriate chemical formulae, with state symbols, on the dotted lines.

[3 mar1<s]

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(b) Use the cycle and the values given in the table to calculate the standard enthalpy of formation of calcium chloride .

[2 marks]

(c) The standard enthalpies of hydration of the Ca 2+ and the cr ions are -1650 kJ mol-1 and -364 kJ mor1 respectively. Use this information and data from the table in part (a) to calculate the enthalpy of solution of calcium chloride.

[2 marks]

(d) The standard enthalpy of solution of ammonium chloride, NH4 CI, is +15 kJ mor1 . A 2.09 sample of ammonium chloride is dissolved in 50 9 of water. Both substances are initially at 20°C. Calculate the temperature change and the final temperature of the solution. Assume that the specific heat capacity of the solution is 4.2 JK-1 9-1. [3 marks]

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3. Aluminium is the first element of Group 13 in the Periodic Table.

(a) State the valence electronic configuration of aluminium

[1 mark]

...................................................................................................................................... (b) When aqueous sodium hydroxide is added to an aqueous solution of aluminium chloride, a white precipitate, P, is formed. This precipitate dissolves in excess sodium hydroxide, fOmling an ion, Q .

(i) Name the precipitate P.

[1 mark]

(ii) What is the formula of ion Q ?

[1 mark]

(c) An aqueous solution of aluminium salt is acidic. (i) Describe what you would observe when aqueous sodium carbonate is added to aqueous aluminium chloride.

(ii) Write an ionic equation for the reaction in (c)

[2 marks]

[1 mark)

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(d) Aluminium chloride can be used as a catalyst in Friedal Crafts alkylation of benz~ne.

(i) Write an equation for the reaction between aluminium chloride and chloromethane to form an electrophile .

[1 mark]

(ii) Use your understanding of acids and bases to explain the role of aluminium chloride in the reaction above .

[2 marks]

...................................................................................................................................... (e) State one property which enables aluminium to be used in overhead electric cables.

[1 mark]

......................................................................................................................................

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4. (a) The diagram shows how to distinguish between propanal and propanone.

Tollen's reagent

+ propanal or propanone --If---,

water

t heat

(i) State the metal ion present in Tollen's reagent.

................. .... ....... ........ ........ .... .. ... .... ........ .... .. .. ............... .. ........... ......... ... ..... ... [1 mark] (ii) State the functional group present in both propanal and propanone .

... .......................................... .. ... ... .. ....... ... .......... ....................... ...................... [1 mark] (iii) Explain why hot water is used .

.. ..... ...................................... .... ..... .... ... ... ......... ......... ......... .. .. ..... .... ... .. ... .... .... [1 mark]

(iv) State what is observed in separate experiments with propanal and propanone.

Propanal ......................................................................................................... ............................................. ......... .. .. .... ....... ....... ....... .. .......... ....... ... .. .... . [1 mark) Propanone .... ...... .......... .. ..... .. ... ...... ........ ..... ......... .... .. .... .. ..... .......... .... ... .. ...... ............................................................................. ... ... ............ ..... .... ..... . [1 mark)

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(b) Adrenaline is a hormone that acts as a stimulant. It has the structural formula shown below.

H

I

HO

H

H~~f-,-,-H HO

CH 3

(i) State the type of isomerism that can exist in the adrenaline molecule. [1 mark]

(ii) Draw the structural formula of the product formed when adrenaline reacts with

NaOH Structural formula

(aq )

Dilute HCI

Structural formula

[2 marks]

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(c) Adrenaline can be synthesized from X via the following steps:

H~HO HO

(X)

LiAI~

HCN --+~

step 1

p

----~

adrenaline Q

step 2

(i) State the type of reaction that is involved in step 1

[1 mark]

(ii) State the condition(s) required for step 2.

[1 mark]

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20 Section B [60 marks]

Answer any four questions in this section. 5. (a) The equation below shows the reaction between ammonia and a hydrogen ion.

In tenns of the electrons involved, explain how the bond between the NH3 molecule and the H+ ions is fonned.

[3 mari<s]

Name the type of bond fonned in this reaction.

(b)

Boiling point data for three hydrides are given in the table below.

Hydride

Relative molecular mass, M,

Bolling pOint! °c

Methane

16

-182

Ammonia

17

- 33

Water

18

100

Explain why these three hydrides have very different boiling points. [4 marks]

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(c) (i) A reaction of nitrogen monoxide is shown below.

The rate of reaction can be found by measuring the concentration of N02 at different times. Define the term rate of reaction. Sketch a graph to show how the concentration of N02 changes with time. Indicate how the initial rate of reaction could be obtained from your graph.

[4 marks]

(ii) In the manufacture of sulphur trioxide from sulphur dioxide, nitrogen monoxide can be used in a two-stage process to increase the rate of production.

Construct an overall equation for the production of S03 from S02. State and explain fully the role of NO in this process.

[4 marks]

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6. (a) (i) Using a solution of ammonium chloride and ammonia as example, explain what is meant by a buffer solution.

[5 marks]

(ii) Calculate the mass of ammonium chloride that needs to be added to 450 cm 3 of 0.10 mol dm·3 ammonia to produce a solution with pH = 9.0

[1<1) of NH3 = 1.7 X 10-5 mol dm-3 ]

[4 marks]

(b) The pK. values of four carboxylic acids are listed in the table below.

Acid

Formula of acid

pI<.

1

CH 3 CH 2COOH

4.9

2.

CH 3CHCIC02H

2.8

3

CH3CCI2COOH

1.4

4

CH 2CICH 2COOH

4.1

(i) Describe and explain the trend in acidic strength shown by acids 1, 2 and 3.

(ii) Give an explanation for the difference in the pKa values for acids 2 and 4. (iii) Calculate the pH of a 0.010 mol dm-3 solution of propanoic acid (acid 1).

[6 marks]

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7. (a) (i) State the trend in the reducing ability of the halide ions from fluoride to iodide. [1 mark)

(ii) State what you would observe when chlorine water reacts with a solution of potassium iodide. Write an equation for the reaction. State the role of chlorine in the reaction. [3 marks)

(iii) Give a reagent which could be used to distinguish between separate solutions of potassium bromide and potassium iodide. State what would be observed when this reagent is added to each of the separate solutions of potassium bromide and potassium iodide. Write an equation for one of the reactions.

Identify a reagent which could be added to the mixtures from the first test to confirm the identity of the halide ions. State what would be observed in each case. [6 marks]

(b) Carbon tetrachloride and silicon tetrachloride behave in different ways when added to water. State how each chloride behaves and explain the difference.

[5 marks]

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8. (a) An aqueous solution of magnesium nitrate and barium nitrate can be differentiated by the addition of dilute sulphuric acid. State what you would observe when the above reaction is carried out. [3 marks]

(b) Compare and explain the solubility in water, for the solid sulphates formed in 8(a).

[7 marks]

(c) The solubility product, Ksp, of magnesium hydroxide has a numerical value of

2.0)( 10-11 • (i) Write an expression for the Ksp of magnesium hydroxide, stating its units.

(ii) Use the value of Ksp given to calculate the concentration of Mg(OH)2 in a saturated solution .

(iii) Explain whether magnesium hydroxide would be more soluble or less soluble in 0.1 mol dm-3 MgS0 4 (aq) than in water. [5 marks]

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9. (a) (i) Write the mechanism of the reaction when 1-chloropropane is refluxed with aqueous sodium hydroxide. Name of the type of reaction involved

[3 marks]

(ii) State and explain how the rate of this reaction changes when

1-chloropropane is replaced by 1-bromopropane.

[3 marks]

(iii) Write equations to show how you would change 1-chloropropane to

[5 marks]

2-chloropropane

(b) The amino acids alanine and serine are shown below.

H

H

I

H 2N-C--cOOH

I

H 2N-C--cOOH

I

I

CH20H

CH3 alanine

senne

(i) Draw the structures of the two dipeptides formed by the reaction of

alanIne with serine. (ii) Name one of the dipeptides formed in b(i).

(iii) Draw the structure of the organic compound formed when one molecule of serine reacts with two molecules of ethanoyl chloride.

[4 marks]

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10. Five organic compounds, A to E, has the molecular formula CSH100. Compounds A, Band C can react with 2,4-dinitrophenylhydrazine, but not with Fehling's solution. Only A and B gives a positive iodoform test. A has a higher boiling point than B . Compounds D and E give a brick red precipitate, P , with Fehling's solution. D is optically active. Reduction of E gives a straight chain compound, F. Based on the information above, identify compounds A to F. Give reasons for your choice. Name compound P. Write any three chemical equations for the reactions above, involving different reagents.

[15 marks]

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Question 1 (a) (i)

00

(1 ) (ii) (8X2X1/8) + (6X2X112)

=8

(1 )

(b) (i) A set of temperature and pressure values where solid, liquid and gas exist in equilibrium.

(1 )

(ii)

liquid

.cUd 5

_ ,.. _ ~

______ __ _______ L - - -

,

0"

! r

,

_ ._.. _- ---.---- :r,'......_- --," .._...._-_.....- 31 ""

--

General sketch of graph .

(1 )

The correct axes.

(1 )

The labellings.

(1 )

(iii) because its triple pOint occurs at a pressure above the normal atmospheric pressure.

(1 )

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p

=5.50 x 8.31 x (24.0+273)

x 10-3

kPa

(1 )

10.0 x10-3 X 44.0

=

(1 )

30.9 kPa

PI = 30.9 + 93 .7 =

(1 )

124.6 kPa

Total: 10 marks

Question 2 (a) Ca 2+(g) + 2e- + 2CI(g) (This is the only answer for the top line) Ca2+(g) + 2e- + CI2(g) Ca+ (g) + e- + CI2 (g) Ca(g) + CI 2 (g) (state symbols and electrons essential) Note: CI2to 2CI can be in any order but Ca must be in sequence) Max. 3 marks

(1) (1) (1) (1)

(b) Enthalpy of formation = 178 + 590 + 1145 + (2 x 121) - (2 x 364) - 2237 = - 810 kJ mor1

(1) (1)

(c) flH

=-flH(lattice formation) + :LflH(hydration)

(1)

(or cycle with state symbols, numbers or labels) 2237 -1650 - (2 x 364) -141 kJ mor1

= =

(1)

(d) Moles of NH4CI = 2153.5 = 0.0374 Heat absorbed = 15 x 0.0374 = 0.561

(1)

Q=mcflT flT= Qlmc =(0.561x1000)/(50 x4.2) =2.6 (0C) (allow 2.5 to 2.7; can use 52; ignore units, answer must be at least 2 sig figs) Final temperature = 20 - 2.6 = 17.4 °c (Answer is for 20 - previous ans; must be < 20)

(1) (1)

Note; may not use moles (loses first 2 marks) so fl T (15 x 1000)/(50 x4.2) So answers of 71.4 and 68.7 score last 2 out of first 4. (allow no units for temperature, penalise wrong units)

=

Total: 10 marks

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Question 3 (a)

3s2 3p1

(1 )

(b) (i) aluminium hydroxide

(1 )

(ii) AI(OH)4 -

(1 )

(c) (i) white precipitate

(1)

Effervescence (ii) AI(H20)6 ]3+

(1)

+ H20 _

AI(H 20)s(OH)f+

(1 )

(d) (i)

AICh + CH3CI

(1 )

(ii)

as lewis acid

(1 )

In AICI3 ,AI has an incomplete octet and accepts a pair of electrons from the CI atom in CH 3CI @

AICh is an electron-deficient compound. and acts as an

(1 )

electron-pair acceptor. (e) light

(1 )

Total = 10 marks Question 4 (a)

(i)

Ag+/silver

(1 )

=0

(ii)

Carbonyl or C

(iii)

Helps to speed up the reaction/slow at room temperaturelflammable (1)

(iv)

Propanal: silver mirror formed

(1 )

Propanone: no change/solution remains colourless

(1 )

optical isomerism

(1 )

(b) (i)

(1)

(ii)(a) H

r

Na(}-~~ -I-I~ Na~ Hb H

cH,

(1 )

(13)

(1 )

(c) (i) nucleophilic addition (ii) dry ether, room temperature

(1 ) (1 )

Total = 10 marks

r

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Question 5 (a) Lone pair donated / both electrons supplied by one atom

(1 )

from N (to W) [ignore missing charge or hydrogen atom)

(1)

dative/dative covalent/coordinate bonding

(1 )

(b) Van der Waals ( or VrNV) forces between methane molecules

(1)

(or VdW forces in methane) Hydrogen bonding in ammonia and water

(1 )

Hydrogen bonds are stronger than van der Waals forces

(1)

( or VdW forces are the weakest) Hydrogen bonds in water more extensive than ammonia because 0 has two lone (1 )

pairs (N one) [or Water forms more H bonds per molecule (than ammonia») (or H bonds in water stronger because 0 more electronegative than N) (or H bonds in water stronger because 0 - H bond more polar than N - H)

(c) (i) The change in concentration per unit of time Both axes must be labelled to gain marks for graph. y axis cone N0 2 and x axis time Curve starts at origin and levels off.

(1) (1) (1)

Note: If candidates graph does not level off then second mark can be scored for a CUNe with a continuously decreasing gradient.

Initial rate can be found by finding the gradient at t = 0 (1) Note: Candidates may score this mark if they have shown this on their graph (1 ) NO is a catalyst

(1)

it is regenerated at the end of the reaction

(1 )

provides an alternative route of lower activation energy

(1)

Total

=15 marks

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Question 6 (a) (i) A buffer solution has the ability to resist changes in pH when a little acid or base is added .

(1 )

When a little acid is added, it reacts with NH3. The acid is used up, pH remains unchanged NH3

(1 )

+

H+

NH/

(1 )

When a little base is added, it reacts with OW The base is used up, pH remains unchanged NH/

(ii)

(1)

+ OH-

(1)

pOH = 14.0 - 9.0 = 5.0

(1 )

.v =Pftb + Iog [NH;1 [ NH,J

(1 )

IU

p QL1

=-log1.7x10-5 + log [NH/] 1 0.10 [NH/] =0.17 mol dm-3 mass of NH CI in 450 cm 3 =0.17 x 53.5 x 450/1000 = 4.1 g 5.0

(1) (1 )

4

(b) (i) acid strength increases from no. 1 to no. 3 or down the table or as number of CI increase due to the electron-withdrawing effect or electronegativity of chlorine (atoms) stabilising the anion or weakening the O-H bond NOT H+ more available

(1) (1) (1)

(ii) chlorine atom is further away (from O-H) in no. 4, so has less influence

(iii) either: pH = pKa - IOg10 [acid) or Ka = 10 - pKa = 1.259 x 10-3 (4.9 + 2) [H+) ="(Ka. c) 3.55 x 10"" '"' 3.4 (allow 3.5) pH =3.4 Note: [1) for correct expression & values; [1] for correct working Total

=

=

(1)

(1) (1)

=15 marks

--

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Question 7 (a) (i) Increase (ii) Colourless solution tums to a brown solutionl black ppt (need both colours) CI 2 + 2KI ~ 12 + 2 KCI CI 2 is an oxidising agent (iii)

Add silver nitrate solution KBr forms creamy ppt KI forms yellow ppt AgN0 3 + KBr ~ AgBr + KN03 or AgN03 + KI ~ Agi + KN03 or ionic equations Then add (dilute or conc) ammonia AgBr/ cream ppt dissolves in conc NH3 or slightly dissolves in dilute NH3 Agi is insoluble in dilute or conc NH3

(b) SiCl, reacts/hydrolyses, CCl, does not [This must be clearly stated and not just implied] (lone) pair of electrons (from the oxygen atom) in a water molecule cannot form a bond with/be donated to the C atom Or cannot be accepted by C atom

(1)

(1) (1) (1) (1 ) (1) (1) (1) (1) (1) (1) (1)

(1) (1)

because C has no available orbital OR no 3d orbitals in C OR C is a small atom surrounded by CI atoms OR CI atoms are large and surround C atom (so attack is sterically hindered) Rejects CCI 4 has no d orbitals Si has (available) 3d orbitals Rejects SiCI4 has available 3d orbitals

(1 )

(1)

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Question 8 (a)

(b)

white precipitate formed for barium nitrate

(1)

no visible change for magnesium nitrate

(1 )

H2S04(aq) + Ba(N03h - -.. ..

BaS04(s)

Ba 2+(aq)

BaS04(s)

+

SO/-(aq)

+

2HN03 (aq)

@ (1 )

ionic size of Mg2+ < Ba 2+

(1)

magnitude of hydration energy of Mg2+ »

8a 2+

(1)

sol-» size of cations Mg2+ and 8a2+

(1)

magnitude of lattice energy for MgS04 slightly more than 8aS04

(1)

ionic size of

LiHsolution =

(1 )

LiHhydration -LiH lattice

For MgS04 • LiHsolution

=exothermic; For BaS04 • LiHsolution =endothennic ; (1)

barium sulphate - inscluble in water; magnesium sulphate - soluble (c) (i)

(Ksp =) [Mg 2+][OH1 2 3

(1)

9

units are mol dm-

=

(ii) Let [Mg(OHh(aq)) [Mg2+] Ksp 2 X 10-11 4x3 x 1_71 X 10-4 mol dm-3

=

=

=

(1)

(1)

=x (1) (1)

(iii) less soluble because of the common ion effect or the equilibrium Mg(OHh(s) --> Mg2+(aq) + 20W(aq) is moved to the left

(1 ) Total = 15 marks

to

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Question 9 (a) (i) CH 3CH 2

CH3CH 2

H-) - :-

He- +

";:H 2CH 3

1

HO - /

CI -

H

,,- CI

H

_

HO-C -

+C~

""H

H

(1 )

(1) bimolecular nucleophilic substitution

(ii)

H

(1 )

rate increases. atomic size of Br>CI . Hence the C-Br bond is weaker and )s easier to break than C-CI bond ! " <'Ii: . C

(iii)

I '\.I .~

r ~I

(1) (1) (1 )

.

reflux (1) ., --;,Co... ~ C.H3CH2CHiOH ( (1 )

+ NaCI

--------....

CH 3CHCIC H3

(1 ) (b) (i)

(1 )

f

H2N-C

I·

(ii)

Y

C-N-C-COOH

II

I

CH20H 0

H

(1)

1

CH3

serylalanine or alanylserine

penalise polymer both times

(1 )

(iii) H

I

H C-C-o-CH - C-COOH 3

II

o

-

1

1'H 0

0

(1 )

I

CH3

Total = 15 marks

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Question 10 They don't react with Fehling's solution - they are ketones

(1)

A and B gives positive iodoform test - they have the structure CH3 C = 0 or methylketone I

(1)

Boiling point of A> B - A is less branched compared to B A is CH3COCH2CH2CH3

(1) (1)

o and E gives a positive test with Fehling's solution

(1)

- they are aldehydes

o is optically active. Hence isomers of 0 are

(2) Reduction of E gives a long chain compound, F E is CH 3CH 2CH 2CH 2CHO F is CH3CH2CH2CH2CH20H

(1 )

Pis copper(l) oxide (reject CU20) Examples of equations:

(1 ) (3)

«H3 CH 3CH2CH 2C=O

+

(1 )

~

H2NNH--\Q,>-- N02

-- _

Total = 15 marks

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