practice questions from aqa past papers

with answers from aqa mark scheme

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  • Created on: 16-12-10 17:18
Preview of practice questions from aqa past papers

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How Science Works
Suggest two reasons why all of the points do not lie on the line of best fit.
any two sensible errors eg
timing errors and / or example
measurement errors and / or
example
apparatus errors and / or example
human / experimental / random
error and / or example or .did not
do it right.
temperature fluctuation
anomalous point
results not recorded correctly
plotting error
rate calculated incorrectly
Discuss the economic, safety and environmental factors to be considered when there is
an ammonia factory near a town.
any one from:
economic
large town provides workforce
workers do not have to travel far to
the factory. (owtte)
transport infrastructure already in
place for large town. (owtte)
factory brings prosperity to town
(owtte)
factory provides employment
reduced tourism
reduction in local house prices
any other sensible economic factor
linked to town
any one from:
safety
escape of dangerous / harmful
chemicals / gases (owtte)
danger of increased traffic
risk of explosion.(owtte) /danger of
high pressure
consequences of an accident could be
severe if the town is close
any other sensible safety idea
The mass lost by the positive electrode should equal the mass gained by the
negative electrode.
Suggest two reasons why the results were not as expected.

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Explain why sun creams containing nanoparticles should be tested further.
any one from:
may be toxic (to cells / specific
cells)
to ensure safety
or reduce risk
or risk of litigation
nanoparticles may have different
properties
to see if they pass into the body
Suggest why some companies that make sun creams might not want to do more tests.
any two sensible ideas from eg:
testing is expensive
or testing costs money
testing is time consuming
don.…read more

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Percentage yield
Method 2 has the higher atom economy.y.
any two sensible ideas from eg:
no / less waste
less materials / reactants needed /
used
fewer / no environmental
problems or less / no pollution
better for sustainable
development / resources running
out
more useful use of atoms
less purification / separation of
products owtte
The study found that each company used different tests.
The perfumes were tested in the companies' own laboratories and not by independent
scientists.…read more

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Nanoparticles
Suggest and explain why the hip replacement made of nanocrystalline metal should last
longer than one made of normal metals.…read more

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Electrolysis:?
electric current / electricity
plus one from:
is passed through ionic compound /
substance / electrolyte
passed through molten/aqueous
compound / substance
causing decomposition
Describe and explain how electrolysis is used to make pure copper from a lump of
impure copper.…read more

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Covalent
Suggest and explain why silica is used to make bricks for hightemperature furnaces.
In your answer, you should refer to the structure of, and bonding in, silica.…read more

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The carbon contacts are made of graphite. Springs push the contacts against the copper ring.
The contacts conduct electricity to the copper ring. The copper ring rotates rapidly but does
not stick or become worn because the graphite is soft and slippery.
Graphite has properties which are ideal for making the contacts in an electric motor.
Explain, in terms of structure and bonding, why graphite has these properties.
.....................................................................................................................................................…read more

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Metals
Explain how metals conduct electricity
any two from:
outer shell electrons / electrons in
highest energy level (in metals)
electrons are delocalised / sea of
electrons
electrons are free or electrons
move around or electrons are free
to flow or electrons attracted to
positive terminal
electrons carry charge / current or
electrons form the current /
electrons transfer charge /
electrons pass charge
Explain why the gel containing ions in solution can conduct electricityions can move / are attracted to
electrode
or
attracted to…read more

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Rates of Reaction
Copper oxide reacts much faster with acid at 40 ºC than at 20 ºC.
Explain why in terms of particles.
............................................................................................................................................
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............................................................................................................................................…read more

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Acids
Copper sulfate (CuSO4) is a salt that has many uses.
An aqueous solution of copper sulfate can be made by reacting copper oxide (CuO) with an
acid.
3 (a) (i) Name this acid. .........................................................................................................
(1 mark)
3 (a) (ii) Write a balanced symbol equation, including state symbols, for this reaction.
..................................................................................................................................
(2 marks)
sulfuric accept H2SO4
accept sulphuric
allow phonetic spellings
1
3(a)(ii) CuO + H2SO4 CuSO4 + H2O
5 (b) Another compound that the ancient Egyptians used is laurionite.…read more

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