ajc h2chem 2007 prelims paper 1

7/21/2019 AJC H2CHEM 2007 Prelims Paper 1

1/15

ANDERSON JUNIOR COLLEGE2007 PRELIMINARY EXAMINATION

CHEMISTRY 9746/01

Higher 2

Paper 1 Multiple Choice

Monday 17 SEPTEMBER 2007 1 hour

Name : _________________________________ Reg. No.: ______ PDG : ______

INSTRUCTIONS TO CANDIDATES

Do NOT open this question booklet until you are told to do so.

Do not use staples, highlighters, glue or correction fluid on the optical answer sheet (OAS).

There are fortyquestions on this paper. Answer all questions.

For each question there are four possible answersA, B , Cand D. Choose the one you considercorrect and record your choice in soft pencil in the separate answer sheet provided.

Each correct answer will score the mark. A mark will not be deducted for a wrong answer.

Do not write anything on the Data Booklet. Any rough working should be done in this booklet.

You may use a calculator.

INFORMATION FOR CANDIDATES

Additional Materials : Data BookletOptical Answer Sheet (OAS)

Shading of Optical Answer Sheet (OAS)

Shade the last 5 digits of your NRIC / FIN number. Do NOTshade the reference letter.

Section 2 Subject title : H2 Chemistry

Section 3 Test name : 2007 Prelim Exam

This question paper consists of 15 printed pages including this page.

ajc/H2prelim/paper 3/2007 1


2/15

1 Chlorine gas is a severe irritant to the eyes and respiratory system. Themaximum safe toleration level of chlorine gas in air is 0.005 mg dm-3.

How many chlorine atoms are present in 500 cm3of air at this toleration level?

A 2310635.5

0.005

B 23106271

1

1000

0.005

C 231062

1

71

0.005


D 2310671

1

1000

0.005

2 10 cm3 of a hydrocarbon was mixed with 100 cm3 of oxygen gas which is inexcess. The mixture was exploded and after cooling to room temperature, theresidual gases occupied a volume of 80 cm3. Upon passing the residual gasesthrough sodium hydroxide, this volume decreased to 50 cm3. What is the formulaof the unknown hydrocarbon?

A C3H6 B C3H8 C C4H8 D C4H10

3 Flask Xcontains 1 dm3of helium at a pressure of 2 kPa and flask Ycontains 2dm3of neon at a pressure of 1 kPa.

If the flasks are connected at constant temperature, what is the final pressure?

A3

11 kPa B

3

21 kPa C

2

11 kPa D 2 kPa

4 Which of the following contains only one unpaired electron?

A Ga B Se C Te+ D As+


3/15

5 Which one of the following pairs has permanent dipole permanent dipoleinteractions between molecules Iand II?

Molecule I Molecule II

A CHCl3 CH4

B CCl4 CClF3

C CClF3 CHCl3

D C2H5Cl C2Cl4

6 The successive ionization energies, in kJ mol-1, of an unknown element E are

given below.

420 3100 4400 5900 8000 9600 11400 13300

Which of the following statements about Eis correct?

A Eis in group IIof the Periodic Table.B The oxide of Eis an amphoteric oxide.C The chloride of Ehydrolyses in water to give an acidic pH.D Element Ecan conduct electricity in the solid and molten state.

7 Which one of the following sets of solid elements includes a giant metallicstructure, a macromolecular structure and a simple molecular structure?

A Na Mg CB Mg Al SC C Si SD Al Si S

8 The reduction of the iron ore, Fe2O3 by carbon monoxide is an exothermicreaction which occurs in the upper part of the furnace.

Fe2O3(s) + 3CO (g) 2Fe (s) + 3CO2(g) H = 27 kJ mol1

Given that Hffor CO2(g) = 394 kJ mol

1and Hffor CO (g) = 110 kJ mol1,

what is the standard enthalpy change of formation of the iron ore?

A + 257 kJ mol1B + 825 kJ mol1

C 257 kJ mol1

D 825 kJ mol1



4/15

9 A typical protein forms several hundreds of hydrogen bonds and severalthousands of Van der Waals forces in folding from primary to tertiary structures.Which of the following thermodynamic state functions of the protein bestrepresents the folding process?

G / kJ mol

1

H / kJ mol

1

S / J K

1

mol

1

A < 0 < 0 < 0

B < 0 < 0 > 0

C > 0 > 0 > 0

D > 0 > 0 < 0

10 Electroplating is an electrolytic process of coating an object with a thin layer ofmetal.

Which of the following factors will affect the mass of chromium deposited at thecathode during the process of coating chromium on utensil?

A Size of the anodeB Size of the cathodeC Size of the currentD Concentration of the electrolyte

11 Zinc oxide reacts with hydrogen according to the following equation.

ZnO(s) + H2(g) Zn(s) + H2O(g)

At temperature Tand a total pressure of 10 atm, it is found that initial amounts of1 mole each of zinc oxide and hydrogen gas produce 0.01 mole each of zinc andsteam at equilibrium. What is the approximate value of Kpat temperature T?

A 10-5 B 10-2 C 10 D 100

12 What is the pH of the resultant solution when equal volumes of a solution of pH 1

and a solution of pH 3 are added together?

A 1.3 B 1.5 C 2.0 D 2.5



5/15

13 The reaction of nitrogen monoxide with hydrogen

2NO (g) + 2H2 (g) N2 (g) + 2H2O (g)

is thought to involve the following steps:

2NO (g) + H2(g) N2O (g) + H2O (g) (slow)N2O (g) + H2(g) N2 (g) + H2O (g) (fast)

Which of the following statements is correct?

A Hydrogen is reduced by nitrogen monoxide.B The reaction is second order with respect to H2.C The rate equation for the reaction is: rate = k[NO]

2[H2].D N2O acts as a catalyst in this reaction.

14 The percentage of ammonia obtainable at equilibrium during the Haber processis plotted against the operation pressure for two temperatures, 400C and 500C.

Which of the following correctly represents the two graphs?

A B

C D



6/15

15 The ionic radius of the elements in Period 3 (Na to Cl) changes across the period.

Which of the following statements does not explain the trend of the ionic radiusacross the period?

A Across the period, there is an increase in nuclear charge.B The anions have greater screening effect than the cations.C There is constant screening effect among the cations.D The effective nuclear charge decreases from P3-to Cl-.

16 Figure 1shows the first six ionisation energies of an element X.Figure 2 shows the first ionisation energy of eight consecutive elements(including X) of Period 3.

1st IE (across Period 3)

atomic number

1stionisation

energy

/kJ

m

ol-1

1st 6 ionisation energies of X

1 2 3 4 5 6

no. of electron(s) removed

ionisation

energy

/kJ

m

ol-1

D

C

BA

Figure 1 Figure 2

With reference to Figure 2, which of the options corresponds to the firstionisation energy of element X?

17 Which of the following statements is true about the trends in the properties of theGroup VIIelements (Cl2to I2)?

A The volatility increases down the group.B The electronegativity increases down the group.C The oxidising power decreases down the group.D The colour intensity decreases down the group.



7/15

18 Chlorine gas is pumped continuously into hot aqueous potassium hydroxide.Which anions are formed?

A Cl-and ClO

-

B Cl-and ClO3-

C Cl-and ClO4-

D ClO- and ClO3-

19 Use of the Data Booklet is relevant to this question.

Peroxodisulphate(VI), S2O82-, is capable of oxidising the tartrate ion,

[CH(OH)CO2 ]2 to carbon dioxide and methanoate as shown in the following

reaction.

H

C CO2-HO

CO

H

C 2-

HO

+ 3S2O82- + 2H2O 2CO2 + 2HCO2

- + 6H+ + 6SO42-

The reaction can be catalysed by a homogenous catalyst. Given that theelectrode potential for the tartrate ion is

C-

HO

H

CO2

C CO2-

HO

H

2CO2+ 2HCO2-

+ 6H

+

+ 6e + 2H2O E

= + 0.56V

Which metal ion is not a suitable catalyst for this reaction?

A Co3+ B Mn3+ C Fe3+ D V3+

20 Compound Gis optically active.

Cl

C

Cl

H

C O

H

How many chiral centre(s) does compound Ghave?

A 1 B 2 C 3 D 4



8/15

21 Oxidation of an alkene Ygives a diol; further oxidation gives a diketone. Whichone of the following could be Y?

A CH3CH=CH2

B CH3CH=CHCH3

C CH3CH=C(CH3)2

D (CH3)2C=C(CH3)2

22 Benzene reacts with chlorine as shown:

C6H6 + Cl2 C6H5Cl + HCl

Which term describes this type of reaction?

A Free radical substitutionB Electrophilic substitutionC Electrophilic additionD Nucleophilic addition

23 1 mole of an organic compound P undergoes elimination on reaction withethanolic sodium hydroxide to form 2 moles of HBr.

What could Pbe?

A B

Br

CH2CHCH3

Br

Br

CH2Br

C D

BrCH2 C CH2Br

CH3

CH3

CH3 C CH3

Br

Br



9/15

24 When an organic compound Q was treated with phosphorus pentachloride,fumes of hydrogen chloride were evolved. When Q was warmed with alkalineaqueous iodine, a yellow precipitate was formed.

Which of the following was Q?

A CH3COOH

B CH3COCH2CH3

C (CH3)3COH

D CH3CH(OH)CH2CH3

25 The anti-bacterial drug tetracyclinehas the formula

OH

NH2

OOOOH OHOH

CH3HONH3C CH3

Which statement about tetracyclineis correct?

A It does not react with SOCl2.

B It reacts with sodium carbonate to liberate carbon dioxide gas.C 3 moles of HBr is formed when 1 mole of tetracyclinereacts in an excess

of aqueous bromine in the dark.D It reacts with sodium metal to liberate H2gas.

26 Which of the following pair of compounds would produce the same carboxylicacid upon hydrolysis?

A CH3CH2COCl CH3CO2CH3

B CH3CH2CN CH3CO2CH2CH3

C CH3CH2CN CH3CH2CO2CH3

D C6H5CONH2 C6H5NHCOCH3



10/15

27 Oestrone, a sex hormone, has the following structural formula.

HO

OCH3

Which reagent would be expected to react with this compound?

A lithium aluminium hydrideB concentrated sulphuric acidC alkaline aqueous iodineD acidified potassium manganate(VII)

28 A nitrile Xundergoes the following two reactions:

Nitrile X

product,C2H5NH2

product

reduction hydrolysis

What would be produced when the products from the two reactions are mixedtogether?

A [ CH3CH2NH3+ ] [ O2CCH3]

B [ CH3CH2NH3+ ] [ O2CCH2CH3 ]

C CH3CONHCH2CH3

D CH3CH2CONHCH2CH3



11/15

29 Which sequence shows the nitrogen compounds in increasing order of basicstrength?

least basic most basic

ACH3 C

ONH2

NH2ClCH3 NH

CH3

BCH3 C

O

NH2 CH3 NH

CH3

NH2Cl

CCH3 NH

CH3

NH2ClCH3 C

O

NH2

D NH2ClCH3 C

O

NH2 CH3 NH

CH3

30 A sample of serineis dissolved in a buffer solution of pH 12.

H2N CH COOH

CH2

OH

serine

Which form will be predominant at this pH?

A B

H3N CH COO-

CH2

OH

H3N CH COOH

CH2

OH

C D

H2N CH COO-

CH2

OH

H2N CH COO-

CH2

O-



12/15

For each of the questions in this section one or more of the three numbered statements1to 3may be correct.

Decide whether each of the statements is or is not correct (you may find it helpful to puta tick against the statements which you consider to be correct.)

The responsesAto Dshould be selected on the basis of

A B C D

1, 2and 3

are correct

1and 2only

are correct

2and 3only

are correct

1only

is correct

No other combination of statements is used as a correct response

31 In which of the following reactions is the bond angle in the product greater thanthat in the reactant?

1 H2O(l) + H+(aq) H3O

+(aq)

2 C2H4(g) + H2(g) C2H6(g)

3 CO2(g) + OH(aq) HCO3

(aq)

32 A cell with a standard potential, E , of +1.53 V is shown below usingconventional notation.

cell

Zn |Zn2+(aq) ||Fe

3+(aq), Fe2+(aq) |Pt

Which of the following changes, when made separately to the set-up above, will

not affect the E ?cell1 Adding water to the Fe

3+/Fe

2+half-cell

2 Increasing the size of the zinc electrode

3 Increasing the concentration of zinc ions



13/15

33 Hydrogen sulphide gas is bubbled into an acidified solution containing 0.10 moldm-3 of zinc sulphate and 0.10 mol dm-3 of copper(II) sulphate at 15C. Theconcentration of S2-(aq) in the solution at this point is 10-35mol dm-3.

The solubility product of zinc sulphide at 15C is 10-24 mol-2 dm-6 and that of

copper(II) sulphide is 10

-40

mol

2

dm

-6

.

Which of the following statements are correct?

1 Zinc sulphide is more soluble than copper(II) sulphide at 15C.2 Only copper(II) sulphide is precipitated.3 The solubility products of zinc sulphide and copper(II) sulphide will

decrease when the concentration of S2-(aq) is increased.

34 Which graph would confirm that the rate of decomposition of hydrogen peroxide

is first order with respect to the concentration of hydrogen peroxide?

1 rate

[H2O2]

2 [H2O2]

time

3 rate

[H2O2]

35 Which of the following statements are true about the elements of Group II(Mg toBa) and their oxides?

1 Their oxides are basic.2 The elements react with steam to give hydrogen.3 The solubility of the oxides increases down the group.



14/15

36 Vanadium has the electronic structure 1s22s22p63s23p63d34s2. Which compoundis likely to exist?

1 V2O5

2 VOCl

3 K2V2O7

37 Which of the following compounds will give a white precipitate when heated withaqueous silver nitrate?

1 C6H5CH2Cl

2 C6H5COCl

3 C6H5Cl

38 Which of the following reagents can be used to distinguish between the followingtwo compounds?

CH2CH3

OHCH2CH2OH

1 Br2(aq)

2 KMnO4

3 Na

39 Which of the following statements are true for compoundA?

CH2CH

O

HOOC

A

1 It gives a orange precipitate with 2,4-dinitrophenylhydrazine.2 It gives a silver precipitate with Tollens reagent.3 It undergoes esterification with phenol.



15/15

40 The structure of the herbicide Karbutilateis shown below.

OC

O

NHC(CH3)3

NHC

O

N(CH3)2

What would be formed by prolongedboiling of Karbutilatewith aqueous sodiumhydroxide?

1

O-Na+

NHCO2-Na+

2

O-Na+

NH2

3 H2NC(CH3)3

------ END OF PAPER ------


ajc h2chem 2007 prelims paper 1

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