chemistry

1. the diagram shows the result of dropping a purple crystal into water.
after
water five hours
—_—_—_——_—___> purple
purple solution
crystal
which processes take place in this experiment?
| serge | aresra soning |
reaction
a v jv x
b j x x
cc x x v
d x jv v

2 which row about elements, mixtures and compounds is correct?
metallic non-metallic f
mixture compound

element element
a copper methane brass sulfur
b brass sulfur copper methane
cc copper sulfur brass methane
d brass methane copper sulfur

3 the atomic structures of four particles, w, x, y and z, are shown.
[earns | reuters | pons |

www 2 2 2
xx 2 2 3
bd 2 3 2
z 3 2 3

which particles are isotopes of the same element?

a wandx b wandyy c xandy d xandz

4 which statement explains why isotopes of the same element have the same chemical properties?
a_ they have the same number of outer shell electrons.
b_ they have the same number of neutrons.
c_ they have different numbers of protons.
d_ they have different mass numbers.

5 nitrogen forms a nitride ion with the formula n*.
which particle does not have the same electronic configuration as the nitride ion?
a al* b cr cc na* d oo

6 which row describes the formation of single covalent bonds in methane?
a atoms share a pair of electrons both atoms gain a
noble gas electronic structure
b atoms share a pair of electrons both atoms have the same number
of electrons in their outer shell
cc electrons are transferred from one both atoms gain a
atom to another noble gas electronic structure
d electrons are transferred from one both atoms have the same number
atom to another of electrons in their outer shell

7 which formula is an empirical formula?
a c2h,o
b  c,4hso2
c c3h7cooh
d ch3;ch2,ch,cooh

8 heating iron sulfide, fes», in air produces sulfur dioxide.
4fes, + 110, > 2fe,0; + 8so,
what is the maximum mass of sulfur dioxide produced from 120 kg of iron sulfide?
a 64kg b  128kg c 240kg d 512kg

9 which substance produces hydrogen and bromine when electrolysed?
a concentrated aqueous copper(ii) bromide
b_ concentrated aqueous sodium bromide
c_ dilute aqueous potassium bromide
d_ molten lead(ii) bromide

10 which statements about hydrogen fuel cells are correct?
1 water is formed as the only waste product.
2 both water and carbon dioxide are formed as waste products.
3 the overall reaction is 2h2 + o2 > 2h20o.
4 the overall reaction is endothermic.
a 1and3 b 1and4 c 2and3 d 2and4

11 ethene gas, c2h,, is completely burned in excess oxygen to form carbon dioxide and water.
the equation for this exothermic reaction is shown.
coh, + 302 + 2co, + 2h,o0
the table shows the bond energies involved in the reaction.
bond energy
in kj/mol

c=c 614

c-h 413

o=o 495

c=o 799

o-h 467
what is the total energy change in this reaction?
a -954kj/mol
b -1010kj/mol
c -1313kj/mol
d -1369kj/mol

12 which row describes the effect on the activation energy and the frequency of particle collisions
when the temperature of a chemical reaction is increased?
activation frequency
energy of collisions
a increases increases
b no change increases
cc increases no change
d no change no change

13 solid copper(ii) sulfate exists in two different forms, anhydrous and hydrated.
one of these forms is blue and the other is white.
the change between these two forms is reversible.
blue form = white form
what is the blue form and how is the change from the blue form to the white form brought about?
[ee | as
a anhydrous add water
b anhydrous heat
cc hydrated add water
d hydrated heat

14 sodium ions, na*, and oxygen ions, o*, combine with chromium ions to form a salt.
the salt sodium dichromate has the formula nazcr2o7.
what is the oxidation state of chromium in this salt?
a +2 b +3 cc +6 d +12

15 the concentration of hydrogen ions in 100cm? of 0.1 mol/dm* hydrochloric acid is higher than the
concentration of hydrogen ions in 100 cm? of 0.1 mol/dm? ethanoic acid.
which statement explains the difference in hydrogen ion concentration?
a_ ethanoic acid is an organic acid.
b_ ethanoic acid has a lower ph than hydrochloric acid.
c_ ethanoic acid is partially dissociated.
d_ ethanoic acid is a strong acid.

16 which oxide is classified as an amphoteric oxide?
a aluminium oxide
b_ calcium oxide
c_ copper(ii) oxide
d nitrogen oxide

17. which method produces the salt copper(ii) carbonate?

a_ add copper(ii) oxide to water, then add excess aqueous sodium carbonate. filter off the
precipitate.

b_ add copper(ii) oxide to dilute sulfuric acid, then add excess aqueous sodium carbonate.
filter off the precipitate.

c_ add copper to dilute hydrochloric acid, then add aqueous sodium carbonate. filter off the
precipitate.

d_ add copper(ii) oxide to excess aqueous sodium carbonate. filter off the precipitate.

18 which statements about the trends across a period of the periodic table are correct?
1 aluminium is more metallic than sodium.
2 beryllium is more metallic than carbon.
3 boron is more metallic than lithium.
4 magnesium is more metallic than silicon.
a i1and2 b 1and3 c 2and4 d 3and4

19 some information about elements in group ii of the periodic table is shown.
. 3
metal is added to cold water gfe polntg
beryllium no reaction 1.85 1280
magnesium >300 seconds 1.74 650
calcium 60 seconds 1.54 850
strontium 30 seconds 2.62 768
barium 10 seconds 3.51 714
which row shows the correct trends in reactivity, density and melting point of the elements going
down group ii of the periodic table?
p| resciviy | eensty |r point |
a decreases down group increases down group decreases down group
b decreases down group decreases down group no clear trend
cc increases down group no clear trend increases down group
d increases down group no clear trend no clear trend

20 anew element oxfordium, ox, was discovered with the following properties.
solubilit electrical formula bonding ina
y conduction of element molecule of ox2
insoluble in water does not conduct

in which group of the periodic table should the new element be placed?

a_ group ill

b- group v

c_ group vii

d_ group viii

21 which row describes a similarity and a difference between chlorine and bromine?
[sia atrence

a both are gases at room chlorine and bromine

temperature and pressure have different colours
b both exist as chlorine is more

diatomic molecules dense than bromine

cc both have atoms with only bromine will react with

seven outer-shell electrons aqueous sodium chloride
d both react with aqueous chlorine is more reactive

potassium iodide than bromine

22 which statement describes transition elements?
a they have high densities and high melting points.
b_ they have high densities and low melting points.
c_ they have low densities and high melting points.
d_ they have low densities and low melting points.

23 which gas is made when powdered zinc is added to dilute hydrochloric acid?
a carbon dioxide
b_ chlorine
c hydrogen
doxygen

24 the diagram represents the structure of a solid.
foelerene
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ok xl
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which solids does the diagram represent?
| | brass graphite sodium chloride
a v v x
b v x x
cc x v jv
d x x v

25 steel is an alloy of iron.
which statement explains why steel is stronger than iron?
a_ steel contains carbon which is a very hard substance.
b_ the carbon atoms in steel bond together very strongly.
c_ the carbon atoms in steel make the iron atoms bond together very strongly.
d_ the carbon atoms prevent layers of iron atoms from sliding over each other.

26 three students, x, y and z, are told that solid p reacts with dilute acids and also conducts
electricity.
the table shows the students’ suggestions about the identity of p.
which students are correct?
a x,yandz b xonly c yonly d zonly

27 which statement explains why aluminium appears to be unreactive?
a_itis coated in an oxide layer.
b_ it has a low density.
c _itis low in the reactivity series.
d_itis solid at room temperature.

28 during the electrolysis of aluminium oxide, the mass of the carbon anode changes.
which row describes the change and gives a reason for this change?
mass change argh
of the anode
a decreases carbon reacts to form carbon dioxide
b decreases carbon dissolves in molten cryolite
cc increases electrodes become coated with cryolite
d increases electrodes become coated with aluminium

29 several processes are used to treat domestic water.
which row identifies a reason for the given process?
ee
a chlorination removes impurities
b filtration removes insoluble solids
cc sedimentation removes soluble solids
d use of carbon kills bacteria

30 what is the equation for photosynthesis?
a co, + 3h, > ch30h + h20
b 6co, + 6h,o0 - cghi20g + 602
c cehi20, —- 2c2h;0h + 2co,
d coehi20g + 602 + 6co2 + 6h2o

31 which statement describes how the c—h bonds in methane gas in the atmosphere contribute to
global warming?
a_ they absorb thermal energy from the sun and emit some of this energy into space.
b_ they absorb thermal energy from the sun and emit all of this energy towards the earth.
c_ they absorb thermal energy from the earth and emit all of this energy towards the earth.
d_ they absorb thermal energy from the earth and emit some of this energy towards the earth.

32. the structural formulae of two hydrocarbons are shown.
ch3ch2ch2ch3 ch3ch(chs3)ch3
which statement about the hydrocarbons is correct?
a they are both alkenes.
b_ they decolourise aqueous bromine.
c_ they are structural isomers.
d_ they undergo addition reactions.

33 the structural formula of compound q is given.
ch3ch2ch2,cooch2ch2ch3
what is compound q?
a butyl butanoate
b butyl propanoate
c propyl butanoate
d propyl propanoate

34 the fractional distillation of petroleum is shown.

which fraction contains hydrocarbons with the longest chain length?
c —~ fuel gas

— —-a

— —.b

— l c

——p —- d

petroleum —>

ad —> bitumen

35 which equation represents the cracking of an alkane?
a 3c2hs, > cohi2
b  cehi2 + h2 > cohia
c cehig > 6c + 7h2
d cehig > cohg + cahio

36 what is the structure of the product of the reaction of propene with bromine?
a b cc d
h h h h br h h br h h h h
rttdio wtded wt dt ot tts
hod hob wad had

37 in reaction r, 2000 molecules of ch2=chp react to form a single molecule x only.
2000 ch2=ch2 > x
which terms describe reaction r, ch2=ch2 and x?
a addition monomer polymer
b addition polymer monomer
cc substitution monomer polymer
d substitution polymer monomer

38 part of the structure of a polymer is shown.
h (@) h o
le
ld
which statements about the polymer are correct?
1 the polymer is nylon.
2 the polymer is formed by condensation polymerisation.
3. there are ester linkages between the monomers.
a 1and2 b 2and3 c 2only d = 3only

39 the concentration of acids and alkalis can be determined by titration.
which pieces of equipment are needed to perform a titration?
1 2 3 4
a i1and2 b 1and3 c 2and3 d 2and4

Solve 0620_s23_qp_21