chemistry

1 this question refers to isolated gaseous atoms.
in which atom are all electrons paired?
a ba b br c ss d si

2 which compound has a boiling point that is influenced by hydrogen bonding?
a ch3;cho b ch3;0ch3 c hco2ch3 d hco2h

3 which fuel would produce the largest mass of coz when 10kg of the fuel undergo complete
combustion?
a biodiesel, c;7h3402
b_ ethanol, c2hgo
c_ octane, cghi8
d_ propane, c3h,

4 the diagram shows the boltzmann distribution of energies in a gas. the gas can take part in a
reaction with an activation energy, e,. the gas is maintained at a constant temperature.
p
proportion of
molecules with |
a given energy
0 ' i
0 e,
molecular energy
which statement is correct?
a if acatalyst is added, peak p will be lower and e, will move to the left.
b_ if acatalyst is added, peak p will be lower and e, will move to the right.
c_ ifacatalyst is added, peak p will be the same and e, will move to the left.
d_ if acatalyst is added, peak p will be the same and e, will move to the right.

5 which molecule has no overall dipole?
a chcl b  ch.cl c chcl; d ccl,

6 which solid contains more than one type of bonding?
a iodine
b - silicon dioxide
c _ sodium chloride
d= zinc

8 ethanedioate ions, c20,*, react with a suitable reagent to form co:. a half-equation for this
reaction is shown.
c,0,7 + 2co, + 2e°
which row is correct?
oxidation state of ioe of reaction
carbon in c,0,7" yp
a +3 oxidation
b +3 reduction
cc +5 oxidation
d +5 reduction

9 oxidation numbers should be used to answer this question.
a redox reaction takes place between hydroxylammonium ions, [nh3oh]*, and acidified iron(iii)
ions, fe**. the products are iron(ii) ions, fe**, h* ions, water and a compound of nitrogen.
the mole ratio of reacting hydroxylammonium ions to reacting iron(ii) ions is 1:2.
which nitrogen-containing compound could be formed in the reaction?
a nh; b n20 cc no d no,

10 element x has a higher first ionisation energy than element y.
two students state what they believe is one factor that helps to explain this.
student 1 “x has a higher first ionisation energy than y because an atom of x has more
protons in its nucleus than an atom of y.”
student 2 “x has a higher first ionisation energy than y because x has a smaller atomic
radius than y.”
only one of the two students is correct.
what could x and y be?
popo
a carbon boron
b magnesium aluminium
cc oxygen nitrogen
d oxygen sulfur

11 hydrogen ions catalyse the hydrolysis of esters.
which statement is correct?
a_ the hydrogen ions act as a heterogeneous catalyst.
b_ the hydrogen ions are in the same phase as the reactants.
c_ the hydrogen ions are used up in the reaction.
d_ the hydrogen ions have no effect on the activation energy of the reaction.

12. silicon is heated in an excess of chlorine, producing compound j.
excess water is added to the sample of j produced.
which row is correct?
is hcl produced
structure of j when water is
added to j?

a giant molecular no

b giant molecular yes

cc simple molecular no

d simple molecular yes

13 which element has the second smallest atomic radius in its group and the third lowest first
ionisation energy in its period?
a boron
b_ calcium
c magnesium
d_ sodium

14 chlorine reacts with cold aqueous sodium hydroxide to produce sodium chloride, water and

compound x.
chlorine reacts with hot aqueous sodium hydroxide to produce sodium chloride, water and
compound y.
what are the oxidation states of chlorine in compound x and compound y?
pf x | ey

a -1 -5

b -1 +5

cc +1 -5

d +1 #5

15 in which reaction does ammonia behave as a br@nsted-lowry base?
a nh; + ch3ch2br > ch3ch2nh2 + hbr
b nh; + h20 + co. > (nh,s)hco3
c 2nh3 + 2na > 2nanh2 + he
d 4nh3 + 302 + 2n2 + 6h20

16 aqueous silver nitrate is added to a solution of potassium iodide.
aqueous ammonia is then added.
what would be observed?
a acream precipitate that dissolves on addition of aqueous ammonia
b= acream precipitate that does not dissolve on addition of aqueous ammonia
c_ a yellow precipitate that dissolves on addition of aqueous ammonia
da yellow precipitate that does not dissolve on addition of aqueous ammonia

17 oxides of nitrogen are present in the environment due to natural and man-made sources.
which row is correct?
[ [natura source ofnitogen oxides [man-made source ofnitogen odes |
a electrical discharges in the atmosphere internal combustion engines
b electrical discharges in the atmosphere as a by-product of the haber process
cc decomposition of dead plants in rivers internal combustion engines
d decomposition of dead plants in rivers as a by-product of the haber process

18 when 3.00g of an anhydrous nitrate of a group 2 metal is decomposed, 1.53g of gas is
produced.
what is the nitrate compound?
a beryllium nitrate
b_ calcium nitrate
c magnesium nitrate
d strontium nitrate

19 which row correctly describes one property of barium and one property of barium oxide?
observation when ph of solution obtained when
barium metal is a spatula measure of bao is
added to water added to 100 cm? of water
a a few gas bubbles 8
form on the metal surface
b a few gas bubbles 13
form on the metal surface
cc rapid effervescence is seen 8
d rapid effervescence is seen 13

20 fructose is a sugar with more than one chiral centre. the fructose molecule is shown with x, y
and z indicating three carbon atoms.
oh
nbn
xx n99
ae
a
y a
h—c—h
z ra he
fructose
which carbon atoms are chiral centres?
a x,yandz b xandyonly c= xonly dy only

21 which pair of alcohols are isomers of each other?
a __ butan-1-ol and 2,2-dimethylpropan-1-ol
b_ butan-2-ol and 2-methylpropan-2-ol
c_pentan-1-ol and 2-methylpropan-2-ol
d_propan-2-ol and 2-methylpropan-2-ol

22 sodium methoxide, na*ch3;0°, reacts with 2-chloro-2-methylpropane in a _ nucleophilic
substitution reaction. the nucleophile is the ch3o7 ion.
which row is correct?
intermediate or rodent
transition state d
a (ch3)3c* (ch3)3coch3
b (ch3)3c* (ch3)3cch2oh
c | [hoch2- - -c(chs)3- - -cl] hoch2c(chs)s3
d [hsco- - -c(chs)3- - -c1]- h3coc(chs3)3

23 which alcohol can be dehydrated to give two products which are structural isomers of each
other?
a b cc d
h h h h h hch, h h h hch,
| | | | | | | | | | |

24 which reagent could detect the presence of alcohol in a mixture consisting mainly of alkanes and
alkenes?
a na
b- brp (in ccl4)
c kmno.(aq)
d 2,4-dinitrophenylhydrazine

25 compound q
e contains a chiral centre,
e gives a positive result with fehling’s reagent,
e gives a positive result with alkaline aqueous iodine.
what could compound q be?
a 1-hydroxybutanone
b  2-hydroxybutanal
c_ 3-hydroxybutanal
d  3-hydroxybutanone

26 what is the mechanism for the reaction of ethanal, ch;cho, with hydrogen cyanide, hcn, in the
presence of nacn?
o [or fe
c| sin vj
a ch,—c—h — > =~ — — + h
or cn cn
an -of h—c==n oh
| | u |
b ch,—c—h — > “—— —_ oh i + 3cn-
con. cn cn
(oy h—c==n oh oh
| u | |
c ch,—c—h —, ch;—_c—h — > “ys
con: cn
d initiation hcn ——® he + °cn
oo o-
; y |
propagation ai | + +cn —~ is
h cn
l it
il + h—cn — “3 + cn
cn cn
l r"
termination al ie + he —s ai i
cn cn

27 ethyl propanoate is refluxed with aqueous sodium hydroxide. the alcohol produced is then
reacted with methyl propanoic acid to make a second ester.
what is the structural formula of this second ester?
a b
i i
— ee eee
ch, ch,
cc d
i i
= ee we ee ee ae
ch, ch,

238 wvnicn reagent could be used to carry out the following reaction?
[\—o — [ne
oh
a_asolution containing acidified dichromate(v1) ions
b_asolution containing dilute, acidified manganate(vii) ions
c_ asolution containing hot, concentrated, acidified manganate(vii) ions
d_ concentrated sulfuric acid

29 four reactions of propanoic acid to form salts and other products are shown.
which reaction does not show the formulae of all the correct products?

a b

ch,ch,co, k*(aq) + h,0(i) (ch,ch,co,-),mg**(aq) + h,(g)
ah jew
ch,ch,co,h(aq)
propanoic
na,co, acid ca(oh),

cc d

ch,ch,co, na*(aq) + co,(g) (ch,ch,co,-),ca?*(aq) + h,o()

30 compound x contains three carbon atoms. part of a simplified infra-red spectrum of compound x
is shown.
100
transmittance
50
0
4000 3000 2000 1500 1000 500
wavenumber/cm-'
which compound could be x?
a ch3ch2zcho
b  ch3;ch2co2h
c ch3ch2ch20h
d ch3co2ch3

31 one mole of sulfuric acid is used to make an aqueous solution. the solution contains h2so,
molecules, h* ions, so,?" ions and hso,; ions.
which statements are correct?
1 the solution contains 6.02 x 10*° sulfur atoms.
2 the solution contains an exactly equal number of h* ions and hso,_ ions.
3 one mole of so,” ions contains two moles of electrons.

32 which statements are correct?
1 the hydrogen bonds in ice are more regularly arranged than in water.
2 the solidification of water to form ice is exothermic.
3 pure water is less dense than ice.

33 calcium reacts with water to form calcium hydroxide and hydrogen.
ca(s) + 2h2o(i) - ca(oh)(s) + ha(g)
the standard enthalpy change for this reaction is —414kj mol”.
what further information is needed in order to calculate the standard enthalpy change of
formation of calcium hydroxide, ah§ ca(oh),(s)?
1 ah? for h2o(i)
2 ah? for ho(g)
3 first and second ionisation energies of ca

34 which statements are correct when a reversible reaction is at equilibrium?
1 all species are at equal concentration.
2 ~the concentrations of all species remain constant.
3. the rate of the forward reaction equals the rate of the reverse reaction.

35 each of the three mixtures shown can result in a chemical reaction.
which mixtures result in a redox reaction?
1. bromine + hydrogen
2 sodium chloride + concentrated sulfuric acid
3. potassium iodide + silver nitrate

36 which statements correctly describe an oxide of nitrogen acting as an atmospheric pollutant?
1. nitrogen monoxide, no, reacts with oxygen to form nitrogen dioxide which contributes to
acid rain.
2 nitrogen dioxide reacts with sulfur dioxide to form sulfur trioxide which reacts with water to
form sulfuric acid.
3. nitrogen oxides react with unburnt hydrocarbons in sunlight to form other pollutants.

37 polymer z contains the length of polymer chain shown below.
this short length of chain is found many times within the chains of polymer z, although it is not
the repeat unit.
—ch2—chci-—ch2—-
what could be the name of polymer z?
1 poly(2-chloropropene)
2 poly(chloroethene)
3 pvc

38 limonene is found in lemons.
limonene
limonene is heated with concentrated acidified potassium manganate(vii).
which compounds are produced?
1. ch3coch2ch2ch(ch2co>2h).
2 co:
3 chscoch2ch2ch(coch3)ch2co2h

39 chlorofluoroalkanes have been used as the refrigerant in refrigerators but care has to be taken in
disposing of old refrigerators.
which statements about chlorofluoroalkanes are correct?
1. c—clbonds more readily undergo homolytic fission than c—f bonds.
2 care is taken in the disposal of old refrigerators because of possible ozone depletion.
3. c2h,cif is more volatile than c2h..

40 the m, of compound x is 72. the composition by mass of x is 66.7% carbon, 11.1% hydrogen
and 22.2% oxygen. x gives an orange precipitate with 2,4-dinitrophenylhydrazine reagent.
x does not react with fehling’s reagent.
what can be deduced from this information?
1. xisacarbonyl compound.
2 xisaketone.
3. xis butanone.

Solve 9701_s18_qp_11