chemistry

1. why is the boiling point of ammonia, nhsg, higher than the boiling point of phosphine, ph3?
a ammonia molecules are polar; phosphine molecules are not.
b ammonia molecules have significant hydrogen bonding; phosphine molecules do not.
c n-h covalent bonds are stronger than p—h covalent bonds.
d_ there is one lone pair in each ammonia molecule but no lone pair in each phosphine
molecule.

2 neutrons are passed through an electric field. the mass of one neutron relative to =, the mass of
ac atom and any deflection in the electric field is recorded.
which row is correct?
mass of behaviour of beam of
neutron neutrons in an electric field
a 0 deflected
b 1 deflected
cc 0 not deflected
d 1 not deflected

3. the table refers to the electron distribution in the second shell of an atom with eight protons.
which row is correct for this atom?
orbital shape c ><) orbital shape ©)
; number of ; number of
orbital type elaétrons orbital type electrons
a 2 4
b 4 2
cc 2 4
d 4 2

4 which statement describes the bond between carbon and hydrogen in an ethene molecule?
a azbond between an s orbital and an sp’ orbital
b  az_bond between an s orbital and an sp’ orbital
c ac bond between an s orbital and an sp? orbital
d ac bond between an s orbital and an sp? orbital

5 aspirin, cghgo4, m, = 180.0, can be made by a reaction between 2-hydroxybenzoic acid, c7h¢os3,
m, = 138.0, and ethanoic anhydride, cshgo3, m, = 102.0. the balanced equation for the reaction
is shown.

c7h—eo3 + cyheo3 —- cohgoq + cohyor
if a reaction mixture consists of 10.0g of each of the two reactants, what is the maximum mass of
aspirin that can be produced?
a 5.7g b 10.0g c 13.0g d 17.69

6 which diagram correctly describes the behaviour of a fixed mass of an ideal gas? (t is measured
in k.)
a b cc d
constant p constant t constant t constant t
vv p pv pv
0 0 0 0
o t o vv o pp 0 vv

7 anhydrous copper(ii) chloride, cucl2, combines with water to form cucl2.2h20. the standard
enthalpy changes of formation for this reaction are shown in the table.
h,0 —286
cucl, —206
cucl,.2h,o0 —808
what is the standard enthalpy change of the reaction shown?
cuclz + 2h20 — cucl2.2h20
a -1586kj mol"
b -316kj mol"
c -110kj mol
d -30kj mol*

8 xenon hexafluoride, xef., reacts with water.
xef, + 3h20 > xeo3 + 6hf
which statement is correct?
a_ hydrogen is reduced in this reaction.
b_ hydrogen is the only element oxidised in this reaction.
c_ the only element oxidised in this reaction is xenon.
d_ this is not a redox reaction.

9 hydrogen is produced industrially from methane as shown in the equation.
ch,(g) + h20(g) == co(g) + 3h2(g) ah® = +205kj mol"
which conditions would most favour the formation of hydrogen?
[| ressure | temperature |
a high high
b high low
[e low high
d low low

10 the chemical equilibrium shown is formed when ammonia is produced in the haber process.
no + 3h, = 2nh3
the following concentrations are found to be present at equilibrium under certain conditions.
what is the numerical value of k, under these conditions?
a 0.0150 b_ 6.0 cc 10.0 d 66.7

11 the enzyme maltase speeds up the reaction between maltose and water.
maltase
maltose + water ————————» glucose
maltase shows specificity.
which statement describes the specificity of maltase?
a maltase is a biological catalyst and it is a type of protein.
b- maltase is most effective between ph 6.1 and ph 6.8.
c_ maltase lowers the activation energies of the reactions it catalyses.
d_ maltase only speeds up a small number of chemical reactions.

12 which description of the bonding and acid/base nature of aluminium oxide is correct?
[| toneing | aise nature
a simple covalent amphoteric
b giant covalent basic only
cc ionic amphoteric
d ionic basic only

13 xand y are elements of the third period.
x and y are individually heated in excess chlorine. each product is purified and then separately
added to water, producing two solutions. both solutions have a ph of less than 5.
what could be x and y?
a naandp b mgandal c mgand si d siandp

14 an ore contains magnesium carbonate and barium carbonate. a sample of the ore is dissolved in
nitric acid.
how could this solution be processed into a magnesium compound and a separate barium
compound?
a add hcl(aq), filter off the solid barium chloride.
b~ add hcl(aq), filter off the solid magnesium chloride.
c add h2so,(aq), filter off the solid barium sulfate.
d add h2so,(aq), filter off the solid magnesium sulfate.

15 when calcium and calcium hyaride, cah, react separately with water, they each produce a white
solid and a colourless gas. the white solid is the same compound in each reaction.
which statement is correct?
a both ca and cal» produce hp.
b- both ca and cahz produce oo.
c ca produces hz and cah, produces oo.
d ca produces o2 and cahp2 produces hp.

16 when concentrated sulfuric acid is added to solid sodium chloride, hclis formed but not clo.
when concentrated sulfuric acid is added to solid sodium iodide, i is formed.
which statement explains these observations?
a sulfuric acid is an oxidising agent and chloride ions are more easily oxidised.
b_ sulfuric acid is an oxidising agent and iodide ions are more easily oxidised.
c sulfuric acid is a reducing agent and chloride ions are more easily reduced.
d sulfuric acid is a reducing agent and iodide ions are more easily reduced.

17 silver chloride and silver iodide form equilibria when added to water.
agcu(s) = ag*(aq) + cl-(aq) k,= k,
agl(s) = ag*(aq) + t'(aq) k. = kp
each equilibrium position lies well to the left.
silver iodide will not dissolve in aqueous ammonia. silver chloride will dissolve in aqueous
ammonia. another equilibrium is formed.
ag*(aq) + 2nh3(aq) == ag(nhs)o"(aq) ke = kg
the position of this equilibrium lies to the right.
what is the order of magnitude for these three equilibrium constants?
a ki:>k2>kk3
b kk.>k,>kg
c k3>k,>kk2
d k3;>k.>kk;

18 elements and their compounds are important as catalysts.
in which process is a compound used, rather than an element?
a catalytic converters
b_ contact process
c_ haber process
d hydrogenation of alkenes

19 ihe gaseous products of heating a mixture of ca(oh). and nh,4c! are passed through solid cao.
this absorbs water vapour and a gas, w, is collected.
a sample of w is oxidised by cl2(g) to produce two gases, x and y.
x is an element. y is acidic.
y reacts with w to produce z.
what are x and z?
p| x | 2 |
a no cacly
b no nh,cl
cc oz cacl,
d oz nh,cl

20 molecule g is shown.
oo
ok
g
how many chiral centres are present in each molecule of g?
a 1 b 2 cc 3 d 4

21° sibirene, cish24, is reacted with an excess of hbr(g). the major product is x.
excess hbr(g)
seu reaea xx
sibirene
what is the skeletal formula of x?
a b
br
br
br br
cc d
br | br by | br

22 which statement is not correct?
a combustion of pvc produces a highly acidic gas.
b pvc molecules are saturated.
c_ the empirical formula of pvc is the same as the empirical formula of its monomer.
d_ the repeat unit of pvc is {chcichcl}.

23 the presence of a halogen in an organic compound may be detected by warming the organic
compound with aqueous silver nitrate.
which compound would be the quickest to produce a precipitate?
a b cc d
cl f f cl
cl f i f

24 halogenoalkanes react with naoh(aq) either by an sy1 mechanism or by an sy2 mechanism.

the mechanism followed by the reaction depends on the structure of the halogenoalkane.

this question is about the reaction of 3-bromo-3-ethylpentane, (c2hs)3cbr.

which statement is correct?

a the mechanism is sy1, due to the stabilisation of an intermediate anion by three alkyl
groups.

b the mechanism is sy1, due to the stabilisation of an intermediate cation by three alkyl
groups.

c the mechanism is sy2, due to the stabilisation of an intermediate anion by three alkyl
groups.

d the mechanism is sy2, due to the stabilisation of an intermediate cation by three alkyl
groups.

29 vvhichn compound is a secondary alcohol that can be dehydrated to form an alkene with m, = /0?
a b cc d
—~- av —— [on
oh oh oh

26 when 0.0075 mol of alcohol x are completely burnt in excess oxygen and the gases produced
are passed through an excess of limewater (calcium hydroxide solution), 3.0g of calcium
carbonate are produced.

when x is warmed with acidified potassium dichromate(vi) there is a colour change from orange
to green.

what could be the identity of x?

a  chs3sch(oh)ch2ch3

b  (chs3)3coh

c chsch2zch20h

d ch3ch(oh)ch3

27 considering only structural isomers, what is the number of alcohols of each type with the formula
c5h120?
[many [secondary | eran
a 3 3 2
b 4 2 2
cc 4 3 1
d 5 2 1

28 a student carried out a two-stage synthesis in which crh3chh2ch2br was converted into
ch3ch2ch2co2h.
which compound could have been formed by the first stage of this synthesis?
a  ch3ch2ch20h
b  chsch2,ch2zcho
c chsch2cn
d ch3;ch2,ch2cn

29 an ester x has the structural formula ch3co2ch(ch3)ch2chs3. x can be prepared by heating an
alcohol y, under reflux, with ethanoic acid and an acid catalyst.
what is the correct name for y?
a __butan-1-ol
b  butan-2-ol
c butan-3-ol
d_ methylpropan-2-ol

30 compound s can be extracted from natural compounds. reacting s with hot, concentrated
kmn0o, produces the organic product, t. some of the absorptions found in the infra-red spectra of
s and t are described.

s has no strong absorption between 1670 and 1740cm™.
t has a strong absorption at 1720cm™ but has no strong, broad absorption between 2500 and
3000cm".
from this information, what could be the formulae of s and t?
a

a ch3(ch2)sch=ch2 ch3(ch2)sco2h

b << \< ch3coch2ch2coch(chs3)2

ch,co
cc ch3coch(coch3)ch2ch2ch(coch3)chs3
d i ho,cch,chzcoch,coch3

31 complete combustion of a sample of a hydrocarbon gave 0.132g of carbon dioxide and 0.054g
of water.
which formulae could correctly represent this hydrocarbon?
1. chs=ch2
2  ch3ch=ch2
3 =ch3sch=chch3

32 which statements are correct?
1 magnesium carbonate decomposes at a lower temperature than calcium carbonate.
2 calcium hydroxide is more soluble in water than magnesium hydroxide.
3 calcium is a stronger reducing agent than magnesium.

33. ammonia and chlorine react as shown.
8nh3 + 3clz > no + 6nh,cl
which statements are correct?
1. each nitrogen atom is oxidised.
2 each chlorine atom is reduced.
3 ammonia behaves as a base.

34 the diagram shows the reaction pathway for a reversible reaction.
energy —n, 190
/kj mol
mo 30
extent of reaction

which statements are correct?

1 the forward reaction is exothermic.

2 the enthalpy change for the forward reaction is —30 kj mol".

3. the enthalpy change for the backward reaction is +90 kj mol.

35 the structure of metals is considered to be positive ions surrounded by delocalised electrons.
the melting points of the metals in period 3 increase with increasing atomic number.
which statements help to explain this trend from sodium to aluminium?
1 the charge on the metal ion increases.
2 there are more delocalised electrons per metal ion.
3. the radius of the metal ion decreases.
a es ee

36 under room conditions, 600 cm” of a gas, x, has a mass of 0.700g.
what could x be?
1. carbon monoxide
2 ethene
3. nitrogen

37 which compounds, on reaction with nabh,, form a compound with a chiral carbon atom?
1. chsch2ch2coch3
2 ch,chcoch2ch3
3 =ch3ch2zcoch2ch3

38 compound y is a straight chain molecule with formula c,h2n+1x. x is a halogen. the m, of y
is 137. the halogen atom is on the second carbon atom in the chain.
which statements are correct?
1. ycontains a chiral centre.
2  ycan eliminate hx to form two structurally isomeric alkenes.
3. ycan eliminate hx to form two geometrically isomeric alkenes.

39 propanone and hydrogen cyanide react together by the mechanism shown.
h.c. h,c oo: h,c oh
vn “\7 na "ny a
c=o — cc h—cn —~> cc + 3cn
/ ls “™ zw ™®
h,c icn- h,c cn h,c cn
which statements about this mechanism are correct?
1. cn is an electrophile.
2 itis an addition reaction.
3. heterolytic bond breaking is involved.

40 acrolein is an organic compound with the molecular formula c3h,o. it is used in water treatment
and as a herbicide. when acrolein reacts with 2,4-dinitrophenylhydrazine an orange precipitate is
obtained. reaction of acrolein with tollens’ reagent produces a silver mirror.

which statements are correct?

1 acrolein reacts with alkaline aqueous iodine to produce a yellow precipitate.
2. acrolein can be reduced to a primary alcohol.

3. acrolein decolourises bromine water.

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