chemistry

1 what are the shapes of the molecules of water and boron trifluoride?
| | mo | em |
a linear pyramidal
b linear trigonal
cc non-linear pyramidal
d non-linear trigonal

2 the electronic configuration of the two outermost shells of an atom is 3s°3p°3d"4s°.
what is this atom?
a manganese
b_ phosphorus
c strontium
d- vanadium

3. drinking water may contain dissolved calcium hydrogencarbonate, ca(hcos3)2.
how many electrons are present in a hydrogencarbonate anion?
a 30 b 31 cc 32 d 33

4 which molecule contains a nitrogen atom with sp hybridised orbitals?
a ch3ch2nh,2 b- hno; c hcn d nh;

2 vvhich mass of solid residue is obtained trom the thermal decomposition of 4.10g of anhydrous
calcium nitrate?
a 0.70g b  1.00g c 1.40g d 2.25g

6 sodium hydroxide neutralises acid.
h* + oh +> h,0
in a 11000dm? sample of an aqueous solution, the concentration of acid, [h"], is
1.26 x 10° °moldm”®.
which mass of solid sodium hydroxide neutralises the acid?
a 0.0214g b_ 0.0504g c 236g d 554g

7 the gas laws can be summarised in the ideal gas equation.
pv=nrt
0.960 g of oxygen gas is contained in a vessel of volume 7.00 x 10m? at a temperature of 30°c.
assume that the gas behaves as an ideal gas.
what is the pressure in the vessel?
a 1.07kpa b 2.14kpa c 10.8kpa d 21.6kpa

8 which equation represents the standard enthalpy change of formation of water?
a ha(g) + 302(g) > h20(g)
b_ hg) + 40,(g) > h2o(l)
c 2h2(g) + o2(g) > 2h20(g)
d 2h2(g) + o2(g) > 2ho(i)

9 hess’ law and bond energy data can be used to calculate the enthalpy change of a reaction.
bromoethane, ch3ch2br, can be made by reacting ethene with hydrogen bromide.
ch2=ch2 + hbr — ch3ch,br
what is the enthalpy change for this reaction?
a -674kjmol*
b -64kjmol*
c +186kjmol"
d +346kjmol"'

10 which reaction is not a redox reaction?
a mg + 2hno3 — mg(nos)2 + he
b  2mg(no3)2 > 2mgo + 4no, + o2
c so, + noz > so; + no
d so; + h20 > hso,

11 the reaction between sulfur dioxide and oxygen is reversible.
2so2 + o2 = 2803 ah® = -196kj mol
which conditions of pressure and temperature favour the reverse reaction?
[| pressure [temperate
a high high
b high low
cc low high
d low low

12 which statement about the effect of a catalyst on a reversible reaction is correct?
a_ the activation energy of the forward reaction stays the same.
b the composition of the equilibrium mixture stays the same.
c_ the rate of the backward reaction stays the same.
d_ the value of the equilibrium constant changes.

13 which oxide is insoluble in aqueous sodium hydroxide?
a mgo b_ al,03 c p4019 d so,

14 x, y and z are three elements in the third period.
e xreacts with chlorine to give a liquid product.
e y reacts with chlorine to give a solid product that dissolves in water to give a
solution of ph 7.
e z reacts with chlorine to give a solid product that dissolves in water to give a solution
of ph 6.
which elements are good conductors of electricity?
a xandy b yandz c yonly d zonly

15 asolution contains both mg”*(aq) and sr**(aq) at the same concentration.
the solution is divided into two equal portions. aqueous sodium hydroxide is added dropwise to
one portion. dilute sulfuric acid is added dropwise to the other portion.
which row is correct?
precipitate seen first precipitate seen first
when naoh(aq) is added when h2so,(aq) is added

a magnesium hydroxide magnesium sulfate

b magnesium hydroxide strontium sulfate

cc strontium hydroxide magnesium sulfate

d strontium hydroxide strontium sulfate

16 the volatility of the group 17 elements, chlorine, bromine and iodine, decreases down the group.
what is responsible for this?
a bond length in the halogen molecule
b bond strength in the halogen molecule
c_electronegativity of the halogen
d number of electrons in the halogen molecule

1/7 bromine is extracted trom sea-water.
in the final stages of the process two redox reactions take place.
br.(aq) + so(g) + 2h2o(1) > 2hbr(aq) + h2so,(aq)
2hbr(aq) + cl2(g) > bro(g) + 2hcl(aq)
which row is correct?
[aie —
oxidising agent oxidising agent

a bro so2 cl,

b cl bro soz

cc clo so2 brz

d so2 bro cl,

18 when burned, sulfur forms a gaseous product x which can be oxidised to produce a gas y.
gas y reacts with water to produce a product z.
which row correctly shows the oxidation states of sulfur in x, y and z?
x y z
a -2 +4 +4
b -2 +4 +6
cc +4 +6 +4
d +4 +6 +6

19 one molecule of ammonia reacts with one molecule of ethyl methanoate, hcq2c2hs, to produce
one molecule of methanamide, hconhg, and only one other molecule, x.
one molecule of methanamide decomposes on heating strongly to produce one molecule of
ammonia and only one other molecule, y.
what could be the identities of x and y?
ee ee
a ethanoic acid carbon monoxide
b ethanoic acid hydrogen cyanide
cc ethanol carbon monoxide
d ethanol hydrogen cyanide

20 which types of stereoisomerism are shown by 2,4-dimethylhex-2-ene?
a both cis-trans isomerism and optical isomerism
b_cis-trans isomerism only
c neither cis-trans isomerism nor optical isomerism
d optical isomerism only

21 anorganic ion containing a carbon atom with a negative charge is called a carbanion.
an organic ion containing a carbon atom with a positive charge is called a carbocation.
the reaction between aqueous sodium hydroxide and 1-bromobutane proceeds by an sy2
mechanism.
what is the first step in the mechanism?
a attack by a nucleophile on a carbon atom with a partial positive charge
b_heterolytic bond fission followed by attack by an electrophile on a carbanion
c_heterolytic bond fission followed by attack by a nucleophile on a carbocation
d_ homolytic bond fission followed by attack by a nucleophile on a carbocation

22 compound x can be converted into compound y in a single step.
oh
xx —_
o o
y
what could be the identity of x?
a b cc d

23 which compound reacts with 2,4-dinitrophenylhydrazine reagent but does not react with tollens’
reagent?
a ch3coco2h
b  chsch(oh)cho
c ch3scocho
d ch3ch(oh)ch3

24 structural isomerism and stereoisomerism should be considered when answering this question.
the molecular formula of compound x is c5h,20.
compound x:
e reacts with alkaline aqueous iodine
e can be dehydrated to form two alkenes only.
what could be the identity of compound x?
a ch3ch2ch(ch3)ch20oh
b  ch3ch2ch(oh)ch2ch3
c (ch3)2chch(oh)ch3
d ch3ch2ch2zch(oh)ch3

29 vvhich volume of hydrogen, measured under room conditions, is produced when 0.160g of
methanol reacts with an excess of sodium?
a 60cm? b  120cm? c 240cm? d 480cm*

26 compound x produces a carboxylic acid when heated under reflux with acidified
potassium dichromate(vi). compound x does not react with sodium metal.
what could be the identity of compound x?
a _propanal
b_propanone
c_propan-1-ol
d_propan-2-ol

27 a _ reaction occurs when a sample of 1-chloropropane is heated under reflux with

sodium hydroxide dissolved in ethanol.
which row is correct?
| | type of reaction name of product

a elimination propan-1-ol

b elimination propene

cc substitution propan-1-ol

d substitution propene

28 ethanedioic acid has the formula ho2cco2h.
what is the formula of aluminium ethanedioate?
a aico, b_ al(c204)3 c al2c20,4 d_ al2(c20,)3

29 alcohols, aldehydes and nitriles can each be converted into carboxylic acids.
which descriptions of their conversions into carboxylic acids are correct?
[| ateonos | atdeyaes [ities

a hydrolysis hydrolysis hydrolysis
b hydrolysis hydrolysis oxidation
cc oxidation oxidation hydrolysis
d oxidation oxidation oxidation

30 how many structural isomers with the molecular formula c4h190 give infra-red absorptions both
at approximately 1200 cm“ and at approximately 3400 cm™'?
a 2 b 4 cc 6 d 7

31 compound q contains 40% carbon by mass.
what could q be?
1 glucose, cgh120¢5
2 — starch, (ceh10os)n
3. sucrose, cy2h2201,

32 acontainer is partially filled with hot water, sealed and left to cool.
which statements are correct?
1 as the temperature decreases, water molecules lose kinetic energy.
2  asthe temperature decreases, more water molecules move from vapour to liquid.
3 as the temperature decreases, the vapour pressure of the water decreases.

33 ammonia and chlorine react together in the gas phase.
8nh3 + 3clz > no + 6nh,ci
which statements are correct?
1 ammonia behaves as a reducing agent.
2 ammonia behaves as a base.
3. the oxidation number of hydrogen changes.

34 in which reactions does nh; behave as a bre@nsted-lowry acid?
1. 2nh3; > nh2 + nh,”
2 hso, + nh3 — so,? + nh,"
3 ag’ + 2nh3 > [ag(nhs)2]”

35 chlorine reacts with hot aqueous sodium hydroxide.
which oxidation states does chlorine show in the products of this reaction?
1 -1
2 +3
3 +1

36 in which different forms does nitrogen exist in compounds?
1. bonded by a triple covalent bond
2 as part of a cation
3 in an oxidation state of +5

37 poly(ethene) and pvc are examples of addition polymers.
which statements are correct?
1. oncombustion, pvc can produce carbon monoxide, carbon dioxide and hydrogen chloride.
2 when poly(ethene) is buried in a landfill site, it will not significantly biodegrade.
3 the empirical formula of an addition polymer is the same as that of the monomer.

38 organic compound x gives a precipitate when warmed with aqueous silver nitrate. this
precipitate dissolves when concentrated aqueous ammonia is added.
what could x be?
1. 1-bromopropane
2 = 2-chlorobutane
3. 2-iodo-2-methylpropane

39 propanal reacts with hydrogen cyanide to form 2-hydroxybutanenitrile. a suitable catalyst for this
reaction is sodium cyanide.
nacn
ch3ch2cho + hcn = ch3ch2ch(oh)cn
which statements about the reaction of propanal with hydrogen cyanide are correct?
1 hcn is a weaker nucleophile than the nucleophile provided by nacn.
2 the reaction mechanism involves two steps.
3. the product of the reaction has a chiral carbon atom.

40 the structure of lactic acid is shown.
(8)
ni
hs. goh
|
oh
lactic acid
which esters might form when lactic acid is heated?
1. ch3ch(oh)co2ch(ch3)co2h
[
ch (@)
o~ n\cf
2 j
of “a
ch,
3 =chsch(oh)co2ch(oh)ch3

Solve 9701_m18_qp_12