chemistry

1. which atom has exactly three unpaired electrons in the ground state?
a anisolated gaseous aluminium atom
b_anisolated gaseous carbon atom
c_ anisolated gaseous chromium atom
d_ anisolated gaseous phosphorus atom

2 which element has the second smallest atomic radius in its group and the second highest
electrical conductivity in its period?
a_ boron
b-calcium
c magnesium
d_ sodium

3. analysis of the hormone thyroxine gives the results shown.
heating 0.500g of thyroxine with aqueous silver nitrate produces 0.604 g of silver iodide. all of
the iodine in the thyroxine sample is converted to silver iodide.
complete combustion of 0.500 g of thyroxine produces 232 cm of carbon dioxide and 7.72 cm? of
nitrogen, measured under room conditions.
which molecular formula of thyroxine agrees with these values?
a cishyinogly m, = 776.6
b  cish7noalg m, = 1280.2
c  caqhasnoely m, = 1002.6
d  cgoh2i1nogle m, = 1506.2

4 how many moles of oxygen, o2, are needed to burn 1mol of ethane if the products of the
reaction are water and carbon only?
a 1.5 b 3 c 3.5 d 5

5 which compound has the smallest difference in electronegativity between its two elements?
a kf b- kbr cc lif d libr

6 vsepr theory should be used to answer this question.
hydrazine has the following structure.
hydrazine
h h
ff
x—>( n—n
\
h h
what is the predicted bond angle x?
a 90° b 107° c 109.5° d 120°

6 a student reacts 1mol of magnesium powder in a sealed 0.030m" container of oxygen at a
pressure of 2.0 x 10°pa and a temperature of 600k. the magnesium reacts completely to form
mgo.

which percentage of the oxygen will be used up?
a 5.0% b 10% c 42% d 83%

9 which equation represents an enthalpy change that is the average bond energy of the c—h bond
in methane?
a 7c(g) + h(g) > 4ch4(g)
b 7ch.(g) > 4c(g) + h(g)
c ch,(g) > c(g) + 4h(g)
d cha(g) > chs(g) + h(g)

10 magnesium carbonate decomposes when heated in a bunsen burner flame.
values for the standard enthalpies of formation, ah, of the species involved are shown.
ah? mgco3 = —1095.8 kj mol
ah® mgo = -601.7 kj mo!"
ah? co = -393.5kj mol
what is the standard enthalpy change for the decomposition of magnesium carbonate?
a +100.6kjmol™
b  +887.6kjmol
c +1095.8kjmol*
d +2091 kj mol"

11 nh,no; decomposes into n20 and h20 on heating.

which statements are correct?
1 the ammonium ion is behaving as a reducing agent.
2 the nitrate(v) ion is behaving as an oxidising agent.
3 it is a redox reaction.
4 it is a disproportionation reaction.

a 1,2,3and4

b 1,2 and 3 only

c 3and4 only

d  3only

12 a student adds 3mol of acidified k2cr207 to an excess of i ions.
the chromium is all reduced to cr** and i” ions are oxidised to ip.
the iz released is reduced back to i" ions by x mol of s,0;7 ions.

1 mol of i, is reduced by 2 mol of s,0;7 ions.
what is the value of x?
a 3 b 6 c 9 d 18

13 which statement about acids and bases is always correct?

a_ an acid with two h atoms per molecule will be stronger than an acid with one h atom per
molecule.

b- aconcentrated solution of a strong acid will have a lower ph than a dilute solution of a weak
acid.

c_ aconcentrated solution of a strong base will have a lower ph than a dilute solution of a weak
base.

d_ asstrong acid is more dissociated in solution than a strong base.

14 the reaction between sulfur dioxide and oxygen is reversible.
2s0.(g) + o2(g) == 2s03(g) — k. = 280 mol‘ dm* at 1000k
in an equilibrium mixture at 1000 k the sulfur trioxide concentration is 6.00 mol dm”.
the sulfur dioxide concentration is twice the oxygen concentration.
what is the sulfur dioxide concentration?
a 0.175moldm*
b  0.252moldm®
c 0.318moldm®
d 0.636 moldm®

15 the boltzmann distribution of the particles in a mixture of gas x and gas y is shown in diagram 1.
diagram 1
percentage
of particles
0
0 energy
x and y react and the reaction causes an increase in gas molecules present. the reaction goes
to completion.
in experiment 1, the increase in volume is measured every 10 seconds. during the reaction, the
temperature and pressure remain constant. the increase in volume is shown in the volume-—time
graph in diagram 2.
diagram 2
increase in
volume /cm?
0
0 time/s
in experiment 2, the experiment is repeated using identical amounts of x and y. a different
temperature is used compared to experiment 1. the same pressure is used. the boltzmann
distribution of the second mixture of x and y is shown in diagram 3. during the reaction the
temperature and pressure remain constant.
diagram 3
percentage
of particles
0
0 energy
which curve on the volume-time graph would show the increase in volume against time for
experiment 2? (the original line for experiment 1 is redrawn as a solid line.)
a
increase in if a
volume/cm® |!; (ce le
an)
0
0 time/s

16 when the temperature of a particular reaction is increased by 10°c (e.g. from 20°c to 30°c) the
rate of the reaction approximately doubles.
what is the most significant reason for this increase?
a adifferent mechanism for the reaction
b_anincreased collision frequency of the reactant molecules
c_ more collisions have energy greater than the activation energy
d  areduced activation energy for the reaction

17 which ion has the smallest radius?
a ai* b ba** c mg” d na*

18 which row is correct?
emer [sear
fifth ionisation energy amphoteric oxide
a aluminium aluminium only
b aluminium both aluminium and phosphorus
cc phosphorus aluminium only
d phosphorus both aluminium and phosphorus

19 each of the chlorides listed is added to water.
1 aluminium chloride
2 magnesium chloride
3 silicon tetrachloride
4 phosphorus pentachloride
which chlorides form an aqueous solution that reacts with sodium carbonate to produce
carbon dioxide?
a 1 and 2 only
b  3and 4 only
c 1,3 and 4 only
d 1,2,3and4

20 naoh(aq) is added to separate samples of magnesium chloride and barium chloride solutions.
h2so,(aq) is then added slowly to each reaction mixture until in excess.
what is observed at the end of the reaction sequence?
mgcl,(aq) bacl2(aq)
a colourless solution only colourless solution only
b colourless solution only white precipitate
cc white precipitate colourless solution only
d white precipitate white precipitate

21 a 4.00g sample of an anhydrous group 2 metal nitrate, z, is heated strongly until there is no
further change of mass. a solid residue of mass 1.37 g is formed.
which metal is present in z?
a barium
b~ calcium
c magnesium
d strontium

22 chlorine is bubbled through a cylinder containing aqueous sodium iodide and an immiscible layer
of hexane.
excess gas out
chlorine gas —»
[= _
aqueous
° sodium iodide
°°
as the bubbles pass through the cylinder, what is observed in the lower and upper layers?
| | lower aqueous layer upper hexane layer
a colourless solution becomes brown colourless liquid becomes coloured
b colourless solution becomes brown colourless liquid is unchanged
cc brown solution becomes colourless colourless liquid becomes coloured
d brown solution becomes colourless colourless liquid is unchanged
i

23 chlorine and bromine have different volatilities.
which row identifies the more volatile of the two elements, and gives the correct explanation?
identity of the explanation for the
more volatile element difference in volatility

a bromine intermolecular forces are greater in
bromine than they are in chlorine

b bromine intermolecular forces are greater in
chlorine than they are in bromine

cc chlorine intermolecular forces are greater in
bromine than they are in chlorine

d chlorine intermolecular forces are greater in
chlorine than they are in bromine

24 ammonium chloride dissolves readily in water.
which statement about the colourless solution formed is correct?
a __lons in the solution can form hydrogen bonds with water molecules.
b_ the solution is slightly basic.
c_ the solution would smell of chlorine.
d when sodium hydroxide is added, a gas is formed which turns damp blue litmus paper red.

25 at 550°c nitrogen dioxide reacts with unburnt hydrocarbon fragments, such as chs, in the
catalytic converter of a motor vehicle.
4ch; + 7no, > 34n, + 4co, + 6h2o
which row gives the energy change for this reaction and a possible reason for it?
energy change reason why the reaction is endothermic
of reaction or exothermic
a endothermic chemical energy is converted to heat energy
b endothermic the n=n bond energy is very high
cc exothermic coz and h20 have negative ah? values
d exothermic double bonds are broken in no,

26 compound x contains an alcohol group and a carbonyl group.
compound x
al
(e)
which row is correct?
type of type of
alcohol group carbonyl group
a primary aldehyde
b primary ketone
cc tertiary aldehyde
d tertiary ketone

27 the diagram shows the skeletal formula of phenazine.
phenazine
nie
soe
what is the empirical formula of phenazine?
a ceh,n b  cehen c ci2hgn2 d  cy2hi2no

28 ine diagram shows the structural formula of mevalonic acid.
mevalonic acid
h ohh 4h
sie pap te de
rhe!
which reagent and conditions will react with mevalonic acid to produce an organic compound
without a chiral carbon atom?
a heat under reflux with ch30h/h*
b_heat under reflux with cr2077-/h*
c_ naatroom temperature
d pci; at room temperature

29 structural isomerism and stereoisomerism should be considered when answering this question.
y is a gaseous hydrocarbon which decolourises aqueous bromine.
10.0g of y occupies a volume of 3.43 dm? under room conditions.
how many isomeric structures are possible for y?
a 4 b 5 c 6 d 7

30 limonene is found in lemon and orange oils.
limonene
what is the major product when limonene reacts with an excess of dry hydrogen chloride?
a b cc d

cl cl

cl cl
cl

cl

31 which statement concerning the hydrolysis of 1-bromopropane with water is correct?
a_ the hydrolysis reaction between water and 1-iodopropane is faster because the c—br bond
is less polar than the c-i bond.
b_ the hydrolysis reaction with water is very slow because water is a weak electrophile.
c the mechanism of the reaction involves the formation of a stable carbocation.
d_ the reaction is slower with 1-chloropropane because the c-—ci bond is stronger than the
c-br bond.

32 compound j, cish23brecl, is reacted with an excess of a hot concentrated solution of
sodium hydroxide in ethanol. one of the products is x.
compound j
excess naoh
cl :
br in ethanol
—— x
br
what could be the skeletal formula of x?
a b cc d

33 structural isomerism only should be considered when answering this question.
several compounds with molecular formula c,hgo2 have one carbonyl group and one oh group.
how many of these compounds produce yellow crystals with alkaline i,(aq) at room temperature?
a 2 b 3 cc 4 d 5

34 pentaerythritol is used as an intermediate in the manufacture of paint.
pentaerythritol
hoch, ch,oh
se
ws
hoch, ch,oh
which statement is correct?
a pentaerythritol can be dehydrated by concentrated sulfuric acid to form an alkene.
b_ the empirical formula and molecular formula of pentaerythritol are different.
c_ pentaerythritol does not react with acidified potassium manganate(vii).
d one mole of pentaerythritol gives two moles of hydrogen gas on reaction with an excess of
sodium.

35 which reaction has a nucleophilic addition mechanism and gives a good yield of product under
the stated conditions?
a 1-bromopropane reacting with hot ethanolic sodium hydroxide
b_ _2-iodopropane reacting with hot aqueous sodium hydroxide
c_propanal reacting with hydrogen cyanide under alkaline conditions
d _propanal reacting with hydrogen cyanide under acidic conditions

36 acarbonyl compound has the structural formula ch3;cocho.
which row is correct for the observations made when this compound is treated with the given
reagents?
| | 2,4-dnph reagent fehling’s reagent
a silver mirror red precipitate
b silver mirror orange precipitate
cc orange precipitate silver mirror
d orange precipitate red precipitate

37 an ester is shown.
h h fe) i
ao | ~ /
i 1 or
|
h—c—h a
i
which two compounds react to form this ester?
a 2-methylpropan-1-ol and propanoic acid
b_  2-methylpropan-2-ol and propanoic acid
c_propan-1-ol and 2-methylpropanoic acid
d  2-methylpropan-2-ol and ethanoic acid

38 which compound can be used to make propanoic acid by treatment with a single reagent?
a = ch2=chch2ch3
b  ch3ch2ch2cn
c ch3ch(oh)cn
d ch3ch(oh)ch3

39 a sample of sulfur consists mostly of “*s. it also contains 4.2% “"s and 2.8% “°s. no other
isotopes of sulfur are present.
what is the relative atomic mass, a,, of this sample of sulfur?
a 32.1 b 32.2 c 34.0 d 34.3

40 one molecule of an addition polymer containing 2000 repeat units has an m, of 112000.
the polymer molecule contains chiral centres.
what is a possible monomer for this polymer?
a  ch2=chch3
b  ch2=c(chs)2
c ch 2=chch2ch;
d chs=chch2ch2ch3

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