AQA GCSE Chemistry paper 2 (triple
higher) - read description (public)
Questions & Answers
How are alloys made? - ANSWERSmelt the metal, mix in the other elements, allow the
mixture to cool to form an alloy
bronze key facts - ANSWERSmade up of copper and tin, used for statues and
decorative items, resistant to corrosion
brass key facts - ANSWERSmade up of copper and zinc, used for door fittings, taps and
musical instruments, it is malleable
aluminium alloys key facts - ANSWERSmade 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 - ANSWERSmade up of gold with many other elements, used for
jewellery, wears away less easily when alloyed with copper
What is rusting? - ANSWERScorrosion of iron
rust = - ANSWERShydrated iron oxide
What are both required for rusting? - ANSWERSwater and air
How can rusting be sped up? - ANSWERSwith salt and other electrolytes eg acids
What forms of sacrificial protection can be used to prevent rusting from happening
quickly? - ANSWERSpaint 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? - ANSWERSAdd 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? - ANSWERS39.5 ml and 40.5 ml.
What is meant by a mole of atoms, ions or molecules? - ANSWERS6.02 x 10^23 atoms,
ions, or molecules
What is phytomining? - ANSWERSPlants 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? - ANSWERSBacteria 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)? - ANSWERSWe can displace the metal (eg copper) using iron, or we can
use electrolysis.
catalyst - ANSWERSSpeeds up a reaction by finding an
alternative pathway with a lower activation energy
activation energy - ANSWERSminimum 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) - ANSWERSenergy to break bonds -
energy to form bonds
What is a life cycle assessment? (LCA) - ANSWERSAn 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! - ANSWERSeg 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
higher) - read description (public)
Questions & Answers
How are alloys made? - ANSWERSmelt the metal, mix in the other elements, allow the
mixture to cool to form an alloy
bronze key facts - ANSWERSmade up of copper and tin, used for statues and
decorative items, resistant to corrosion
brass key facts - ANSWERSmade up of copper and zinc, used for door fittings, taps and
musical instruments, it is malleable
aluminium alloys key facts - ANSWERSmade 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 - ANSWERSmade up of gold with many other elements, used for
jewellery, wears away less easily when alloyed with copper
What is rusting? - ANSWERScorrosion of iron
rust = - ANSWERShydrated iron oxide
What are both required for rusting? - ANSWERSwater and air
How can rusting be sped up? - ANSWERSwith salt and other electrolytes eg acids
What forms of sacrificial protection can be used to prevent rusting from happening
quickly? - ANSWERSpaint 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? - ANSWERSAdd 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? - ANSWERS39.5 ml and 40.5 ml.
What is meant by a mole of atoms, ions or molecules? - ANSWERS6.02 x 10^23 atoms,
ions, or molecules
What is phytomining? - ANSWERSPlants 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? - ANSWERSBacteria 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)? - ANSWERSWe can displace the metal (eg copper) using iron, or we can
use electrolysis.
catalyst - ANSWERSSpeeds up a reaction by finding an
alternative pathway with a lower activation energy
activation energy - ANSWERSminimum 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) - ANSWERSenergy to break bonds -
energy to form bonds
What is a life cycle assessment? (LCA) - ANSWERSAn 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! - ANSWERSeg 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
