AQA GCSE Chemistry paper 2 || All Answers are Flawless.
How are alloys made? correct answers melt the metal, mix in the other elements, allow the
mixture to cool to form an alloy
bronze key facts correct answers made up of copper and tin, used for statues and decorative
items, resistant to corrosion
brass key facts correct answers made up of copper and zinc, used for door fittings, taps and
musical instruments, it is malleable
aluminium alloys key facts correct answers made up of aluminium with many other possible
metals, used for aircraft and plating on tanks/military vehicles, has a very low density
gold alloys key facts correct answers made up of gold with many other elements, used for
jewellery, wears away less easily when alloyed with copper
What is rusting? correct answers corrosion of iron
rust = correct answers hydrated iron oxide
What are both required for rusting? correct answers water and air
How can rusting be sped up? correct answers with salt and other electrolytes eg acids
What forms of sacrificial protection can be used to prevent rusting from happening quickly?
correct answers paint for cars, oil/grease (lubricants) for bikes, coat in plastic, using a metal with
a different reactivity so that it reacts with the air and water FIRST, before the iron (when zinc is
used to coat iron, we call this galvanisation)
,How could one make a ceramic pot? correct answers Add water to clay and mix. Shape it. Heat it
in a furnace to harden.
If a measuring cylinder has an uncertainty of + or - 0.5 ml, what is the minimum and maximum
volume that 40 ml could be? correct answers 39.5 ml and 40.5 ml.
What is meant by a mole of atoms, ions or molecules? correct answers 6.02 x 10^23 atoms, ions,
or molecules
What is phytomining? correct answers Plants are grown on the land containing the metal
compound that we want. The plants absorb the metal compound and concentrate it in their tissue.
The plants are harvested and burned. At the end, the ash contains a relatively high concentration
of the metal compound.
What is bioleaching? correct answers Bacteria are mixed with low grade ore (ore that contains
only a small sample of the metal compound we want). The bacteria carry out chemical reactions
and produce a chemical called a leachate. The leachate contains the metal compound that we
want.
How can metals be extracted from metal compounds (AFTER phytomining or bioleaching)?
correct answers We can displace the metal (eg copper) using iron, or we can use electrolysis.
catalyst correct answers Speeds up a reaction by finding an
alternative pathway with a lower activation energy
activation energy correct answers minimum amount of energy required for a reaction to occur
overall energy change (don't be confused if the word enthalpy is used instead of energy - you do
not need to know the difference at GCSE) correct answers energy to break bonds - energy to
form bonds
, What is a life cycle assessment? (LCA) correct answers An assessment of the impact of a product
on the environment, by looking at its cost and sustainability at each stage, eg extracting and
processing the raw materials, manufacturing and packaging, use and operation during its
lifetime, and disposal (including transport and distribution)
You should be able to compare LCAs, however the information you need will usually be given to
you in an exam as part of an evaluate question. The spec requires you to compare plastic and
paper shopping bags - do this! correct answers eg paper takes a lot of water to produce but paper
is renewable, plastic is non-renewable, may be lighter and therefore take less energy to transport,
it is non-biodegradable which could have a negative impact on ecosystems
What happens when we burn metal ions in oxygen? correct answers In most cases, the flame
changes colour, and in all cases, a metal oxide is formed.
lithium flame colour correct answers crimson (a type of red)
sodium flame colour correct answers yellow-orange
potassium flame colour correct answers lilac
magnesium flame colour correct answers bright white (no specific colour)
calcium flame colour correct answers orange-red
copper flame colour correct answers green
How does flame emission spectroscopy work? correct answers The ions are heated. The
electrons are excited and move into the next energy level. When they drop back to the initial
energy level, they transfer energy as light. This light passes through a spectroscope which detects
the different wavelengths of light and produces a line spectrum. The spectrum's appearance
How are alloys made? correct answers melt the metal, mix in the other elements, allow the
mixture to cool to form an alloy
bronze key facts correct answers made up of copper and tin, used for statues and decorative
items, resistant to corrosion
brass key facts correct answers made up of copper and zinc, used for door fittings, taps and
musical instruments, it is malleable
aluminium alloys key facts correct answers made up of aluminium with many other possible
metals, used for aircraft and plating on tanks/military vehicles, has a very low density
gold alloys key facts correct answers made up of gold with many other elements, used for
jewellery, wears away less easily when alloyed with copper
What is rusting? correct answers corrosion of iron
rust = correct answers hydrated iron oxide
What are both required for rusting? correct answers water and air
How can rusting be sped up? correct answers with salt and other electrolytes eg acids
What forms of sacrificial protection can be used to prevent rusting from happening quickly?
correct answers paint for cars, oil/grease (lubricants) for bikes, coat in plastic, using a metal with
a different reactivity so that it reacts with the air and water FIRST, before the iron (when zinc is
used to coat iron, we call this galvanisation)
,How could one make a ceramic pot? correct answers Add water to clay and mix. Shape it. Heat it
in a furnace to harden.
If a measuring cylinder has an uncertainty of + or - 0.5 ml, what is the minimum and maximum
volume that 40 ml could be? correct answers 39.5 ml and 40.5 ml.
What is meant by a mole of atoms, ions or molecules? correct answers 6.02 x 10^23 atoms, ions,
or molecules
What is phytomining? correct answers Plants are grown on the land containing the metal
compound that we want. The plants absorb the metal compound and concentrate it in their tissue.
The plants are harvested and burned. At the end, the ash contains a relatively high concentration
of the metal compound.
What is bioleaching? correct answers Bacteria are mixed with low grade ore (ore that contains
only a small sample of the metal compound we want). The bacteria carry out chemical reactions
and produce a chemical called a leachate. The leachate contains the metal compound that we
want.
How can metals be extracted from metal compounds (AFTER phytomining or bioleaching)?
correct answers We can displace the metal (eg copper) using iron, or we can use electrolysis.
catalyst correct answers Speeds up a reaction by finding an
alternative pathway with a lower activation energy
activation energy correct answers minimum amount of energy required for a reaction to occur
overall energy change (don't be confused if the word enthalpy is used instead of energy - you do
not need to know the difference at GCSE) correct answers energy to break bonds - energy to
form bonds
, What is a life cycle assessment? (LCA) correct answers An assessment of the impact of a product
on the environment, by looking at its cost and sustainability at each stage, eg extracting and
processing the raw materials, manufacturing and packaging, use and operation during its
lifetime, and disposal (including transport and distribution)
You should be able to compare LCAs, however the information you need will usually be given to
you in an exam as part of an evaluate question. The spec requires you to compare plastic and
paper shopping bags - do this! correct answers eg paper takes a lot of water to produce but paper
is renewable, plastic is non-renewable, may be lighter and therefore take less energy to transport,
it is non-biodegradable which could have a negative impact on ecosystems
What happens when we burn metal ions in oxygen? correct answers In most cases, the flame
changes colour, and in all cases, a metal oxide is formed.
lithium flame colour correct answers crimson (a type of red)
sodium flame colour correct answers yellow-orange
potassium flame colour correct answers lilac
magnesium flame colour correct answers bright white (no specific colour)
calcium flame colour correct answers orange-red
copper flame colour correct answers green
How does flame emission spectroscopy work? correct answers The ions are heated. The
electrons are excited and move into the next energy level. When they drop back to the initial
energy level, they transfer energy as light. This light passes through a spectroscope which detects
the different wavelengths of light and produces a line spectrum. The spectrum's appearance
