ZIMSEC A Level Chemistry Paper 3 November 2009

Question 1

mass spectrometry

The graph shows the mass spectrum of an organic compound X.

Which peak represents the relative molecular mass of X?

AA (43)
BB (77)
CC (105)
DD (120)

Question 2

redox chemistry

An acidic solution of $MnO_4^{2-}_{(aq)}$ undergoes the reaction shown below:

$3MnO_4^{2-}_{(aq)} + 4H^+_{(aq)} \rightarrow 2MnO_4^-_{(aq)} + MnO_{2(s)} + 2H_2O_{(l)}$

Which statement about the reaction is correct?

A $MnO_4^{2-}$ is reduced to $MnO_4^-$
B $MnO_4^-$ is reduced to $MnO_4^{2-}$
C $MnO_4^{2-}$ is oxidised to $MnO_4^-$
D $MnO_4^{2-}$ is oxidised to $MnO_2$

Question 3

transition elements

Which statement about transition elements is correct?

ATheir melting points are lower than s-block elements.
BThey have low densities.
CThey use only 3d orbitals for bonding.
DThey form ions with partially filled d-orbitals.

Question 4

molecular geometry

Which structure represents the gaseous

SnCl_2

molecule?

ACl-Sn-Cl drawn straight (linear), with no lone pair on Sn
BCl-Sn-Cl drawn bent, with no lone pair on Sn
CCl-Sn-Cl drawn bent, with one lone pair on Sn
DSn with a Cl to its left and a Cl below it, and two lone pairs on Sn

Question 5

chemical equilibrium

Nitrogen dioxide decomposes on heating according to the equation:

$2NO_{2(g)} \rightleftharpoons 2NO_{(g)} + O_{2(g)}$

On introducing 4.8 moles of $NO_2$ to a 1 $dm^3$ container, 0.96 moles of $O_2$ were produced at equilibrium.

What is the value of $K_c$ ?

A0.640
B0.480
C0.426
D0.240

Question 6

kinetic theory of gases

Which two assumptions are made in the kinetic theory of gases?

AMolecules are close together but do not attract each other.
BMolecules are large and are widely separated.
CMolecules have no volume and do not attract each other.
DMolecules have the same average kinetic energy and undergo elastic collisions.

Question 7

ideal gases

Which graph shows the variation of volume of an ideal gas with temperature at constant pressure?

AExponential curve (volume increases rapidly with temperature)
BStraight line through origin (linear increase)
CCurve that flattens (volume increases then levels off)
DStraight line with negative gradient (volume decreases with temperature)

Question 8

electronegativity

Which graph shows the change in electronegativity down a group?

AElectronegativity decreases then increases (zigzag pattern)
BElectronegativity increases linearly with atomic number
CElectronegativity decreases smoothly with atomic number
DElectronegativity shows multiple peaks with atomic number

Question 9

reaction kinetics

In a reaction

X + Y \rightarrow 2Z

, it was found that doubling the concentration of X caused the rate to increase four times but doubling Y did not affect the rate. What is the rate equation?

ARate = $k[X]^2$
BRate = $4k[X]^2$
CRate = $4[K]^4$
DRate = $4k[X]$

Question 10

acid strength

Which of the following is the weakest acid in aqueous solution?

AHF
BHCl
CHBr
DHI

Question 11

electrochemistry

Which statement is correct about standard hydrogen electrode?

APressure of hydrogen gas is 0.1 atmospheres.
BConcentration of hydrogen ions is 1.0 $mol/dm^3$ .
CHydrogen ions acquire electrons from the platinum electrode.
DThe cell is at temperature of 398 K.

Question 12

reaction kinetics

The graph shows the decomposition of cyclopropane to propene.

Which statement is correct?

Arate = k[cyclopropane]
Breaction is second order with respect to cyclopropane
Crate of reaction can be followed using colour change
Dhalf-life is 10 seconds

Question 13

reaction kinetics

The diagram below is a Boltzmann distribution curve.

In which region are molecules likely to undergo effective collisions?

Question 14

intermolecular forces

Which statement explains why the boiling point of methane is greater than that of neon?

AMethane has a greater mass than neon.
BMethane has stronger Van der Waals forces than neon.
CMethane has stronger covalent bonds than neon.
DMethane is polar but neon is not.

Question 15

organic reaction rates

Which reaction takes place most rapidly?

A $CH_3I + OH^- \rightarrow CH_3OH + I^-$
B $CH_3COCl + OH^- \rightarrow CH_3COOH + Cl^-$
C $CH_3Cl + OH^- \rightarrow CH_3OH + Cl^-$
D $C_6H_5Cl + OH^- \rightarrow C_6H_5OH + Cl^-$

Question 16

nucleophiles

Which one is the strongest nucleophile?

A $NH_3$
B $CH_3CH_2NH_2$
C $(CH_3CH_2)_2NH$
D $(CH_3CH_2)_3N$

Question 17

redox titration

1.27 g of iron(II) ethanedioate were made up to 250 $cm^3$ of acidified aqueous solution. $x$ $cm^3$ of this solution reacted completely with 26.5 $cm^3$ of 0.02 M potassium permanganate solution.

What is the mole ratio of potassium permanganate to ethanedioate in this reaction?

A3 : 5
B1 : 5
C2 : 5
D1 : 3

Question 18

esterification

Which product is formed when 2-methyl-propanoic acid is heated with ethanol in the presence of a catalyst?

A $CH_3-C(CH_3)_2-CO_2CH_3$
B $CH_3-CH(CH_3)-CO_2CH_2CH_3$
C $CH_3-C(CH_3)_2-CH_2-CO_2CH_2CH_3$
D $CH_3-C(CH_3)_2-CH_2-CO_2CH_3$

Question 19

amino acids

Which is the structure of 2-aminopropanoic acid at pH 10?

A $H_2N-C(CH_3)(H)-COOH$
B $H_3N^+-C(CH_3)(H)-COOH$
C $H_3N^+-C(CH_3)(H)-COO^-$
D $H_2N-C(CH_3)(H)-COO^-$

Question 20

polymers

Kevlar is a fire resistant polymer. Its structure is as shown.

Which monomers are used to make Kevlar?

ABenzoic acid and aniline (phenylamine)
B4-aminobenzamide and nitrosobenzene
C4-aminobenzoic acid and 4-aminobenzamide
DBenzene-1,4-dicarboxylic acid (terephthalic acid) and 1,4-diaminobenzene

Question 21

organic chemistry reactions

Which reaction produces a precipitate with ethanol?

AAlkaline aqueous iodine.
BReaction with ethanoic acid.
CReaction with phosphorous (V) chloride.
DReaction with thionyl chloride.

Question 22

organic synthesis

Chloromethyl benzene is reacted with reagent X to form an intermediate Z which then reacted with Y to give phenylethanoic acid as shown below.

$C_6H_5CH_2Cl \xrightarrow{\text{reagent X}} Z \xrightarrow{\text{reagent Y}} C_6H_5CH_2CO_2H$

Which is a possible combination for reagents X and Y?

ANaCN in aqueous ethanol / dil. $H_2SO_4$
BHCN in aqueous ethanol / $NaOH_{(aq)}$
C $Na_2CO_3$ in aqueous ethanol / $HNO_{2(aq)}$
D $CH_3OH$ / dil. $HCl_{(aq)}$

Question 23

IUPAC nomenclature

What is the name of the given compound?

$CH_3-CH(CH_3)-CH(CH_3)-CH_2-CH_2-CH_3$ with a $CH_2-CH_3$ branch on the third carbon from the left.

A1,1-dimethyl-2-ethylbutane
Bmethylethylpentane
C2-methyl-3-ethylpentane
D3-ethyl-2-methylpentane

Question 24

geometric isomerism

Which of these compounds exhibit cis-trans isomerism?

A $CH_2CBr_2$
B $(CH_3)_2C=CHBr$
C $CH(Br)=CHCH_3$
D $CH_2=CHBr$

Question 25

organic synthesis

$CH_3CH_2CH_2Br$ undergoes the following changes:

$CH_3CH_2CH_2Br \xrightarrow{KCN} X \xrightarrow{LiAlH_4} Y$

What is Y?

A $CH_3CH_2CH_2CN$
B $CH_3CH_2CH_2CH_2CN$
C $CH_3CH_2CH_2NH_2$
D $CH_3CH_2CH_2CH_2NH_2$

Question 26

halogen displacement reactions

Chlorine in cyclohexane was added to aqueous potassium bromide in a test tube, an orange colour was observed on shaking the mixture. Which statement is correct?

AChlorine is oxidised.
BChlorine disproportionates.
CBromine is oxidised.
DBromine is reduced.

Question 27

group IV chemistry

Which are the products of the reaction between

SiCl_4

and water?

ASiO and HCl
B $SiO_2$ and HCl
C $Si(OH)_2$ and HCl
D $SiO_2$ , $H_2$ and $Cl_2$

Question 28

ionisation energies

Which set of successive ionisation energies (kJ/mol) is for a group (IV) element?

A990, 1800, 3400, 4600, 16300, 20000
B790, 3200, 4100, 5100, 7000, 8900
C1240, 2400, 3800, 4710, 5840, 7060
D1390, 2940, 5200, 6750, 8070, 9880

Question 29

group IV chemistry

Which compound has covalent bonds and has a high melting point?

A $SiO_2$
B $SnO_2$
C $PbO_2$
D $GeO_2$

Question 30

electron affinity

Which graph shows the change in electron affinity of the elements chlorine, bromine and iodine?

AElectron affinity increases steadily from Cl to I (proton number 17 to 53)
BElectron affinity stays level then increases sharply at I
CElectron affinity decreases then increases (Cl highest, Br lower, I highest)
DElectron affinity stays flat from Cl to Br then drops sharply to I

Question 31

chemical equilibrium

Which of the following conditions affect the equilibrium position of the reaction:

$CaCO_{3(s)} \overset{\Delta}{\rightleftharpoons} CaO_{(s)} + CO_{2(g)}$ ?

1. catalysts.
2. temperature.
3. pressure.

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 32

reaction kinetics

Which statements on reaction rates are correct?

1. Rate depends on fastest step of reaction.
2. Rate depends on order of reaction.
3. The overall order of a reaction is the sum of orders with respect to reactants involved in rate equation.

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 33

environmental chemistry

Organic acids normally find their way into river water as pollutants. Which substances would react with these pollutants?

1. Calcium hydroxide.
2. Calcium carbonate.
3. Chlorine water.

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 34

periodic trends

The graph shows the changes in properties of the elements Na to Ar.

Which properties are represented by graphs 1, 2 and 3?

1. Ionisation energies.
2. Melting points.
3. Atomic radii.

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 35

electron configuration

Which species has the same electron configuration as $Al^{3+}$ ?

1. $O^{2-}$ .
2. $Cl^-$ .
3. Ar.

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 36

halogen chemistry

What observation is made when concentrated sulphuric acid is added to solid potassium bromide?

1. A brown gas.
2. White fumes.
3. A brown solid.

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 37

environmental chemistry

Sulphur dioxide is a waste product in some industrial process. What damage does it cause to the environment?

1. Destroys vegetation.
2. Death of fish.
3. Green house effect.

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 38

molecular geometry

Which molecules are planar?

1. $NF_3$ .
2. $BF_3$ .
3. $C_2H_4$ .

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 39

organic reactions

In which conversion is NaOH(aq) involved?

$CH_3CH_2CH_2Br$ converts via path 1 to $CH_3CH_2CH_2OH$ , via path 2 to $CH_3CH=CH_2$ , and via path 3 to $CH_3CH_2COOH$ .

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Question 40

carbonyl chemistry

Which compounds will produce orange precipitates on warming with 2,4-dinitrophenylhydrazine?

1. $C_6H_5COCH_3$
2. $(CH_3)_2CO$
3. $C_6H_5OH$

A1, 2 and 3 are correct
B1 and 2 only are correct
C2 and 3 only are correct
D1 only is correct

Chemistry Paper 3 November 2009

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The questions

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Question 17

Question 18

Question 19

Question 20

Question 21

Question 22

Question 23

Question 24

Question 25

Question 26

Question 27

Question 28

Question 29

Question 30

Question 31

Question 32

Question 33

Question 34

Question 35

Question 36

Question 37

Question 38

Question 39

Question 40

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