Download C1 Revision powerpoint

C1 Revision powerpoint
Suitable for:
Yr 10 Dual award
Yr 11 Separate Science
Revision websites:
http://www.creative-chemistry.org.uk/
http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/
http://www.s-cool.co.uk/gcse/chemistry
http://www.docbrown.info/page20/AQAscience2C.htm#Tripe
C1 Revision checklist + slides
C1.1.1 Atoms
a) All substances are made of atoms. A substance that is made of only one sort of atom
is called an element. There are about 100 different elements. Elements are shown in
the periodic table. The groups contain elements with similar properties.
b) Atoms of each element are represented by a chemical symbol, eg O represents an
atom of oxygen, and Na represents an atom of sodium
c) Atoms have a small central nucleus, which is made up of protons and neutrons and
around which there are electrons.
d) The relative electrical charges are as shown:
Proton +1
Neutron 0
Electron –1
e) In an atom, the number of electrons is equal to the number of protons in the
nucleus. Atoms have no overall electrical charge.
f) All atoms of a particular element have the same number of protons. Atoms of
different elements have different numbers of protons.
g) The number of protons in an atom of an element is its atomic number. The sum of
the protons and neutrons in an atom is its mass number.
h) Electrons occupy particular energy levels. Each electron in an atom is at a particular
energy level (in a particular shell). The electrons in an atom occupy the lowest available
energy levels (innermost available shells).

C1.1.2 The periodic table

a) Elements in the same group in the periodic table have the same number of electrons
in their highest energy level (outer electrons) and this gives them similar chemical
properties.
b) The elements in Group 0 of the periodic table are called the noble gases. They are
unreactive because their atoms have stable arrangements of electrons.
C1.1.3 Chemical reactions
a) When elements react, their atoms join with other atoms to form compounds. This
involves giving, taking or sharing electrons to form ions or molecules. Compounds formed
from metals and non-metals consist of ions. Compounds formed from non-metals consist
of molecules. In molecules the atoms are held together by covalent bonds.
b) Chemical reactions can be represented by word equations or by symbol equations.
c) No atoms are lost or made during a chemical reaction so the mass of the products
equals the mass of the reactants.

C1 1.1 ATOMS, ELEMENTS & COMPOUNDS
• All substances are made of atoms
• Elements are made of only one type of atom
• Compounds contain more than one type of atom
• Compounds are held together by bonds
An atom is
made up of
a tiny
nucleus
with
electrons
around it
• Each element has its own
symbol in the periodic table
• Columns are called GROUPS.
• Elements in a group have
similar properties
• Rows are called PERIODS
• The red staircase splits
metals from non-metals
C1 1.2 ATOMIC STRUCTURE
• Atoms contain PROTONS, NEUTRONS & ELECTRONS
• Protons and Neutrons are found in the NUCLEUS
• Electrons orbit the nucleus
PARTICLE
RELATIVE
CHARGE
RELATIVE
MASS
Proton
+1 (positive)
1
Neutron
0 (neutral)
1
Electron
-1 (negative)
0
Any atom contains equal numbers of
protons and electrons
• ATOMIC NUMBER  the number of protons in the nucleus
 the periodic table is arranged in this order
• MASS NUMBER  the number of protons plus neutrons
Number of neutrons = Mass Number – Atomic Number
C1 1.4 FORMING BONDS
•
Atoms can react to form compounds in a number of ways:
i)
Transferring electrons  IONIC BONDING
ii)
Sharing electrons  COVALENT BONDING
IONIC BONDING
COVALENT BONDING
• When a metal and non-metal react
• Metals form positive ions
• Non-metals from negative ions
• Opposite charges attract
• A giant lattice is formed
• When 2 non-metals bond
• Outermost electrons are shared
• A pair of shared electrons forms a bond
CHEMICAL FORMULAE
• Tells us the ratio of each element in the
compound
• In ionic compounds the charges must cancel
out:
E.g. MgCl2
We have 2 chloride ions for every magnesium ion
C1 1.3 ELECTRON ARRANGEMENT
• Electrons are arranged around the nucleus in SHELLS (or energy levels)
• The shell closest to the nucleus has the lowest energy
• Electrons occupy the lowest available energy level
High energy shell
This is how we draw atoms
and their electrons
Sodium
Low energy shell
• Atoms with the same number of electrons in the outer shell belong to the same GROUP in
the periodic table
• Number of outer electrons determine the way an element reacts
• Atoms of the last group (noble gases) have stable arrangements and are unreactive
C1 1.5 CHEMICAL EQUATIONS
• Chemical equations show the reactants (what we start with) and the products (what we
end up with)
• We often use symbol equations to make life easier
CaCO3  CaO + CO2
Ca = 1
C=1
O=3
Ca = 1
C=1
O=3
• This is balanced – same number of each type of
atom on both sides of the equation
• We can check this by counting the number of each
type on either side
MAKING EQUATIONS BALANCE
Equations MUST balance
We can ONLY add BIG numbers to the front of
a substance
We can tell elements within a compound by BIG
letters
CaCO3  this is a compound made of 3
elements (calcium, carbon and oxygen)
H2 + O2  H2O
H=2
O=2
H=2
O=1
Add a 2 to the products side to make the oxygen
balance
H2 + O2  2H2O
H=2
O=2
H=4
O=2
This has changed the number of hydrogen atoms
so we must now adjust the reactant side:
2H2 + O2  2H2O
C1.2 Limestone and building materials
a) Limestone, mainly composed of the compound calcium carbonate (CaCO3), is
quarried and can be used as a building material.
b) Calcium carbonate can be decomposed by heating (thermal decomposition) to
make calcium oxide and carbon dioxide.
c) The carbonates of magnesium, copper, zinc, calcium and sodium decompose on
heating in a similar way.
d) Calcium oxide reacts with water to produce calcium hydroxide, which is an alkali that
can be used in the neutralisation of acids.
e) A solution of calcium hydroxide in water (limewater) reacts with carbon dioxide to
produce calcium carbonate. Limewater is used as a test for carbon dioxide. Carbon
dioxide turns limewater cloudy.
f) Carbonates react with acids to produce carbon dioxide, a salt and water. Limestone
is damaged by acid rain.
g) Limestone is heated with clay to make cement. Cement is mixed with sand to make
mortar and with sand and aggregate to make concrete
  
C1 2.1 LIMESTONE & ITS USES
• Limestone is made mainly of Calcium Carbonate
• Calcium carbonate has the chemical formulae CaCO3
• Some types of limestone (e.g. chalk) were formed from the remains of animals and plants
that live millions of years ago
USE IN BUILDING
HEATING LIMESTONE
We use limestone in many buildings by cutting
it into blocks.
Breaking down a chemical by heating is
called THERMAL DECOMPOSITION
Other ways limestone is used:
Cement = powdered limestone + powdered clay
Concrete = Cement + Sand + Water
Calcium
 Calcium + Carbon
Carbonate
Oxide
Dioxide
CaCO3

CaO
+
CO2
ROTARY LIME KILN
This is the furnace used to heat lots of calcium carbonate and turn it into calcium oxide
Calcium oxide is used in the building and agricultural industries
C1 2.2 REACTIONS OF CARBONATES
• Buildings made from limestone suffer from damage by acid rain
• This is because carbonates react with acid to form a salt, water and carbon dioxide
Calcium + Hydrochloric  Calcium + Water + Carbon
Carbonate
Acid
Chloride
Dioxide
CaCO3 + 2HCl  CaCl2 + H2O + CO2
TESTING FOR CO2
• We use limewater to test for CO2
• Limewater turns cloudy
• A precipitate (tiny solid particles) of calcium
carbonate forms causing the cloudiness!
HEATING CARBONATES
Metal carbonates decompose on heating
to form the metal oxide and carbon
dioxide
MgCO3  MgO + CO2
C1 2.3 THE LIMESTONE REACTION CYCLE
• Limestone is used widely as a building material
• We can also use it to make other materials for the construction industry
Calcium Carbonate + Heat  Calcium Oxide
Calcium Oxide + Water  Calcium Hydroxide (Limewater)
Step 4: Add CO2
Ca(OH)2 + CO2  CaCO3 + H2O
Calcium Carbonate
Limestone
Step 1: Add Heat
CaCO3  CaO + CO2
Calcium Oxide
Calcium Hydroxide
Solution
Step 2: Add a bit of water
Step 3: Add more water & filter
Ca(OH0)2 + H2O  Ca(OH)2 (aq)
CaO + H2O  Ca(OH)2
Calcium Hydroxide
C1 2.4 CEMENT & CONCRETE
CEMENT
Made by heating limestone with clay in a kiln
MORTAR
Made by mixing cement and sand with water
CONCRETE
Made by mixing crushed rocks or stones (called aggregate), cement and sand with water
C1 2.5 LIMESTONE ISSUES
BENEFITS
DRAWBACKS
• Provide jobs
• Destroys habitats
• Lead to improved roads
• Increased emissions
• Filled in to make fishing lakes or for
planting trees
• Noisy & Dusty
• Can be used as landfill sites when
finished with
• Dangerous areas for children
• Busier roads
• Ugly looking
C1.3 Metals and their uses
  
a) Ores contain enough metal to make it economical to extract the metal. The economics
of extraction may change over time.
b) Ores are mined and may be concentrated before the metal is extracted and purified.
c) Unreactive metals such as gold are found in the Earth as the metal itself but most
metals are found as compounds that require chemical reactions to extract the metal
d) Metals that are less reactive than carbon can be extracted from their oxides by
reduction with carbon, for example iron oxide is reduced in the blast furnace to make
iron.
e) Metals that are more reactive than carbon, such as aluminium, are extracted by
electrolysis of molten compounds. The use of large amounts of energy in the extraction of
these metals makes them expensive.
f) Copper can be extracted from copper-rich ores by heating the ores in a furnace
(smelting). The copper can be purified by electrolysis. The supply of copper-rich ores is
limited.
C1.3.3 Properties and uses of metals
a) The elements in the central block of the periodic table are known as transition
metals. Like other metals they are good conductors of heat and electricity and can be
bent or hammered into shape. They are useful as structural materials and for making
things that must allow heat or electricity to pass through them easily
b) Copper has properties that make it useful for electrical wiring and plumbing
c) Low density and resistance to corrosion make aluminium and titanium useful metals.
  
g) New ways of extracting copper from low-grade ores are being researched to
limit the environmental impact of traditional mining. Copper can be extracted by
phytomining, or by
bioleaching.
h) Copper can be obtained from solutions of copper salts by electrolysis or by
displacement using scrap iron.
i) Aluminium and titanium cannot be extracted from their oxides by reduction
with carbon. Current methods of extraction are expensive because:
■ there are many stages in the processes
■ large amounts of energy are needed.
j) We should recycle metals because extracting them uses limited resources and
is expensive in terms of energy and effects on the environment
C1.3.2 Alloys
a) Iron from the blast furnace contains about 96% iron. The impurities make it
brittle and so it has limited uses
b) Most iron is converted into steels. Steels are alloys since they are mixtures of
iron with carbon. Some steels contain other metals. Alloys can be designed to have
properties for specific uses. Low-carbon steels are easily shaped, high-carbon
steels are hard, and stainless steels are resistant to corrosion
c) Most metals in everyday use are alloys. Pure copper, gold, iron and aluminium
are too soft for many uses and so are mixed with small amounts of similar metals
to make them harder for everyday use
  
C1 3.1 EXTRACTING METALS
• A metal compound within a rock is called an ORE
• The metal is often combined with oxygen
• Ores are mined from the ground and then
purified
Whether it’s worth extracting a particular metal
depends on:

How easy it is to extract

How much metal the ore contains
The reactivity series helps us decide the best way
to extract a metal:
 Metals below carbon in the series can be
reduced by carbon to give the metal element
 Metals more reactive than carbon cannot be
extracted using carbon. Instead other
methods like ELECTROLYSIS must be used
THE REACTIVITY SERIES
C1 3.2 IRON & STEELS
• Iron Ore contains iron combined with oxygen
• We use a blast furnace and carbon to extract it (as it’s less reactive than carbon)
• Carbon REDUCES the iron oxide;
Iron (III) Oxide + Carbon  Iron + Carbon Dioxide
• Iron from the blast furnace contains impurities:
 Makes it hard and brittle
• A metal mixed with other elements
is called an ALLOY
 Can be run into moulds to form cast iron
 Used in stoves & man-hole covers
E.g. Steel  Iron with carbon and/or
other elements
• Removing all the carbon impurities gives
There are a number of types of steel
alloys:
us pure iron
 Soft and easily shaped
 Too soft for most uses
 Need to combine it with other elements
Carbon steels
 Low-alloy steels
 High-alloy steels
 Stainless steels
C1 3.3 ALUMINIUM & TITANIUM
Aluminium
Titanium
Property
• Shiny
• Light
• Low density
• Conducts electricity and energy
• Malleable – easily shaped
• Ductile – drawn into cables and wires
• Strong
• Resistant to corrosion
• High melting point – so can be used
at high temperatures
• Less dense than most metals
Use
• Drinks cans
• Cooking foil
• Saucepans
• High-voltage electricity cables
• Bicycles
• Aeroplanes and space vehicles
• High-performance aircraft
• Racing bikes
• Jet engines
• Parts of nuclear reactors
• Replacement hip joints
Extraction
Electrolysis
Displacement & Electrolysis
• Aluminium ore is mined and extracted.
• Alumminium oxide (the ore) is melted
• Electric current passed through at high
temperature
• Use sodium or potassium to displace
titanium from its ore
• Get sodium and magnesium from
electrolysis
 Expensive process – need lots of heat and
electricity
 Expensive – lots of steps involved, &
needs lots of heat and electricity
C1 3.4 EXTRACTING COPPER
COPPER-RICH ORES
LOW GRADE COPPER ORES
These contain lots of copper. There are 2 ways to
consider:
These contain smaller amount of
copper. There are 2 main ways:
1. Smelting
1. Phytomining
• 80% of copper is produced this way
• Heat copper ore strongly in a furnace with air
Copper + Oxygen  Copper + Sulphur
Sulphide
Dioxide
• Then use electrolysis to purify the copper
• Expensive as needs lots of heat and electricity
2. Copper Sulphate
• Add sulphuric acid to a copper ore
• Produces copper sulphate
• Extract copper using electrolysis or displacement
• Plants absorb copper ions from
low-grade ore
• Plants are burned
• Copper ions dissolved by adding
sulphuric acid
• Use displacement or electrolysis
to extract pure copper
2. Bioleaching
• Bacteria feed on low-grade ore
• These produce a waste product
that contains copper ions
• Use displacement or electrolysis to
extract pure copper
C1 3.5 USEFUL METALS
TRANSITION METALS
COPPER ALLOYS
•
Bronze – Copper + Tin
- Tough
- Resistant to corrosion
Found in the central block of the periodic table
Properties:
•
Good conductors of electricity and energy
•
Strong
•
Malleable – easily bent into shape
Uses:
•
Buildings
•
Transport (cars, trains etc)
•
Heating systems
•
Electrical wiring
Example: Copper
1. Water pipes – easily bent into shape, strong,
doesn’t react with water
2. Wires – ductile and conduct electricity
Brass – Copper + Zinc
- Harder but workable
ALUMINIUM ALLOYS
• Alloyed with a wide range of other
elements
• All have very different properties
• E.g. in aircraft or armour plating!
GOLD ALLOYS
• Usually add Copper to make
jewellery last longer
C1 3.6 METALLIC ISSUES
EXPLOITING ORES
BUILDING WITH METALS
Mining has many environmental consequences:
Benefits
• Scar the landscape
• Steel is strong for girders
• Noisy & Dusty
• Aluminium is corrosion resistant
• Destroy animal habitats
• Many are malleable
• Large heaps of waste rock
• Copper is a good conductor and not
reactive
• Make groundwater acidic
• Release gases that cause acid rain
RECYCLING METALS
• Recycling aluminium saves 95% of the energy
normally used to extract it!
• This saves money!
• Iron and steel are easily recycled. As they are
magnetic they are easily separated
• Copper can be recycled too – but it’s trickier as
it’s often alloyed with other elements
Drawbacks
• Iron & steel can rust
• Extraction causes pollution
• Metals are more expensive than
other materials like concrete
C1.4 Crude oil and fuels
  
a) Crude oil is a mixture of a very large number of compounds.
b) A mixture consists of two or more elements or compounds not chemically combined
together. The chemical properties of each substance in the mixture are unchanged. It
is possible to separate the substances in a mixture by physical methods including
distillation.
c) Most of the compounds in crude oil consist of molecules made up of hydrogen and
carbon atoms only (hydrocarbons). Most of these are saturated hydrocarbons called
alkanes, which have the general formula CnH2n+2.
C1.4.2 Hydrocarbons
a) Alkane molecules can be represented in the
following forms:
■ C2H6
H H
l
l
■ H –– C –– C –– H
l
l
H H
  
b) The many hydrocarbons in crude oil may be separated into fractions, each of
which contains molecules with a similar number of carbon atoms, by evaporating
the oil and allowing it to condense at a number of different temperatures. This
process is fractional distillation.
c) Some properties of hydrocarbons depend on the size of their molecules.
These properties influence how hydrocarbons are used as fuels.
C1.4.3 Hydrocarbon fuels
a) Most fuels, including coal, contain carbon and/or hydrogen and may also
contain some sulfur. The gases released into the atmosphere when a fuel burns
may include carbon dioxide, water (vapour), carbon monoxide, sulfur dioxide and
oxides of nitrogen. Solid particles (particulates) may also be released.
b) The combustion of hydrocarbon fuels releases energy. During combustion the
carbon and
hydrogen in the fuels are oxidised.
c) Sulfur dioxide and oxides of nitrogen cause acid rain, carbon dioxide causes
global warming, and solid particles cause global dimming.
d) Sulfur can be removed from fuels before they are burned, for example in
vehicles. Sulfur dioxide can be removed from the waste gases after
combustion, for example in power stations.
e) Biofuels, including biodiesel and ethanol, are produced from plant material.
There are economic, ethical and environmental issues surrounding their use.
  
C1 4.1 FUELS FROM CRUDE OIL
CRUDE OIL
• A mixture of lots of different compounds
[A mixture is 2 or more elements or compounds that are not
chemically bonded together]
• We separate it into substances with similar boiling points
• These are called fractions
• This is done in a process called fractional distillation
HYDROCARBONS
Nearly all the compounds in crude oil are hydrocarbons
Most of these are saturated hydrocarbons called alkanes
Methane
CH4
Ethane
C2H6
Propane
C3H8
General formula for
an alkane is CnH(2n+2)
Butane
C4H10
C1 4.2 FRACTIONAL DISTILLATION
This is the process by which crude oil is separated
into fractions
 These are compounds with similar sized chains
 Process relies on the boiling points of these
compounds
 The properties a fraction has depend on the size
of their hydrocarbon chains
SHORT CHAINS ARE:
 Very flammable
 Have low boiling points
 Highly volatile (tend to turn into gases)
 Have low viscosity (they flow easily)
Long chains have the opposite of these!
Crude oil fed in at the bottom
Temperature decreases up the
column
Hydrocarbons with smaller chains
found nearer the top
C1 4.3 BURNING FUELS
COMPLETE COMBUSTION
POLLUTION
Lighter fractions from crude oil make good fuels
Fossil fuels also produce a number
of impurities when they are burnt
They release energy when they are oxidised 
burnt in oxygen:
propane + oxygen  carbon dioxide + water
These have negative effects on the
environment
The main pollutants are summarised
below
Sulphur Dioxide
Carbon Monoxide
Nitrogen Oxide
• Poisonous gas
• Produced when not
enough oxygen
• Poisonous
• It’s acidic
• Causes acid rain
• Causes engine
corrosion
• Poisonous gas
• Prevents your blood
carrying oxygen
around your body
• Trigger asthma
attacks
• Can cause acid rain
Particulates
• Tiny solid particles
• Contain carbon and
unburnt hydrocarbon
• Carried in the air
• Damage cells in our
lungs
• Cause cancer
C1 4.4 CLEANER FUELS
Burning fuels releases pollutants that spread throughout the atmosphere:
GLOBAL WARMING
GLOBAL DIMMING
• Caused by carbon dioxide
• Caused by particulates
• Causing the average global temperature to
increase
• Reflect sunlight back into space
• Not as much light gets through to the
Earth
SULPHUR DIOXIDE
• Caused by impurities in the fuel
CARBON MONOXIDE
Formed by incomplete combustion
• Affect asthma sufferers
• Cause acid rain  damages plants & buildings
CATALYTIC CONVERTERS
• Reduces the carbon monoxide
and nitrogen oxide produced
• They are expensive
• They don’t reduce the amount of
CO2
Carbon + Nitrogen  Carbon + Nitrogen
Monoxide
Oxide
Dioxide
C1 4.5 ALTERNATIVE FUELS
These are renewable fuels  sources of energy that could replace fossil fuels (coal, oil &
gas)
+
BIODIESEL
ETHANOL
HYDROGEN
• Less harmful to animals
• Easily made by
fermenting sugar cane
• Very clean – no
CO2
• Gives off CO2 but the
sugar cane it comes
from absorbs CO2 when
growing
• Water is the only
product
• Large areas of
farmland required
• Less food produced as
people use it for fuel
instead!
• Hydrogen is
explosive
• Takes up a large
volume  storage
becomes an issue
• Breaks down 5 × quicker
• Reduces particulates
• Making it produces other useful
products
•‘CO2 neutral’ – plants grown to
create it absorb the same amount
of CO2 generated when it’s burnt
-
• Large areas of farmland required
• Less food produced  Famine
• Destruction of habitats
• Freezes at low temps
C1.5 Other useful substances from crude oil
a) Hydrocarbons can be cracked to produce smaller, more useful
molecules. This process involves heating the hydrocarbons to
vaporise them. The vapours are either passed over a hot catalyst or
mixed with steam and heated to a very high temperature so that
thermal
decomposition reactions then occur
b) The products of cracking include alkanes and unsaturated
hydrocarbons called alkenes. Alkenes have the general formula
CnH2n.
c) Unsaturated hydrocarbon molecules can be represented in the
following forms:
■ C3H6
H H H
l
l
l
■ H –– C –– C == C
l
l
H
H
d) Alkenes react with bromine water, turning it from orange to
colourless.
e) Some of the products of cracking are useful as fuels.
  
C1.5.2 Polymers
a) Alkenes can be used to make polymers such as poly(ethene) and
poly(propene). In these reactions, many small molecules (monomers)
join together to form very large molecules (polymers). For example:
H
HH
H
l
l l
l
n C === C C ––– C
l
l l
l
H
HH Hn
ethene poly(ethene)
b) Polymers have many useful applications and new uses are being
developed, for example: new packaging materials, waterproof
coatings for fabrics, dental polymers, wound dressings, hydrogels,
smart materials (including shape memory polymers).
c) Many polymers are not biodegradable, so they are not broken
down by microbes and this can lead to problems with waste disposal.
d) Plastic bags are being made from polymers and cornstarch so
that they break down more easily. Biodegradable plastics made from
cornstarch have been developed.
  
C1 5.1 CRACKING HYDROCARBONS
CRACKING  Breaking down large hydrocarbon chains into smaller, more useful ones
CRACKING PROCESS
SATURATED OR UNSATURATED?
1.
Heat hydrocarbons to a high temp;
then either:
We can react products with bromine
water to test for saturation:
2.
Mix them with steam; OR
3.
Pass the over a hot catalyst
ALKENES (double bond)
Orange  Colourless
EXAMPLE OF CRACKING
Cracking is a thermal decomposition reaction:
800oC
C10H22
Decane
C5H12 + C3H6 + C2H4
Pentane
Propene
Ethene
ALKENES
• These are unsaturated hydrocarbons
• They contain a double bond
• Have the general formula  CnH2n
ALKANES (no double bond)
Stays orange
C1 5.2 POLYMERS FROM ALKENES
PLASTICS  Are made from lots of monomers joined together to make a polymer
MONOMERS
POLYMER
Poly(ethene)
Ethene
HOW DO MONOMERS JOIN TOGETHER?
•
•
•
Double bond between carbons ‘opens up’
Replaced by single bonds as thousands of monomers join up
It is called POLYMERISATION
Simplified way
of writing it:
n
‘n’ represent a large
repeating number
C1 5.3 NEW & USEFUL POLYMERS
DESIGNER POLYMER  Polymer made to do a specific job
Examples of uses for them:
• Dental fillings
• Linings for false teeth
• Packaging material
• Implants that release drugs slowly
SMART POLYMERS  Have their properties changed by light, temperature or other
changes in their surroundings
Light-Sensitive Plasters
Hydrogels
Shape memory polymers
• Top layer of plaster
peeled back
• Lower layer now exposed
to light
• Adhesive loses stickiness
• Peels easily off the skin
• Have cross-linking chains
• Makes a matrix that
traps water
• Act as wound dressings
• Let body heal in moist,
sterile conditions
• Good for burns
• Wound is stitched loosely
• Temperature of the body
makes the thread tighten
• Closes the wound up with
the right amount of force
C1 5.4 PLASTIC WASTE
NON-BIODEGRADABLE
RECYCLING
• Don’t break down
• Sort plastics into different types
• Litter the streets and
shores
• Harm wildlife
• Unsightly
• Last 100’s of years
• Melted down and made into new
products
• Fill up landfill sites
• Saves energy and resources…BUT
BIODEGRADABLE PLASTICS
• Plastics that break down easily
• Hard to transport and
• Need to be sorted into specific
types
• Granules of
cornstarch are
built into the
plastic
DISADVANTAGES OF
BIODEGRADABLE PLASTICS
• Microorganisms
in soil feed on
cornstarch
• Demand for food goes up
• This breaks the
plastic down
• Farmers sell crops like corn to
make plastics
• Food prices go up  less can
afford it  STARVATION
• Animal habitats destroyed to
make new farmland
C1.5.3 Ethanol
a) Ethanol can be produced by hydration of ethane with steam in
the presence of a catalyst.
b) Ethanol can also be produced by fermentation with yeast, using
renewable resources. This can be represented by: sugar carbon
dioxide + ethanol



C1 5.5 ETHANOL
There are 2 main ways to make ethanol
1) FERMENTATION
2) ETHENE
Sugar from plants is broken down by
enzymes in yeast
Hydration reaction  water is added
Ethene + Steam  Ethanol
Sugar + Yeast  Ethanol + Carbon Dioxide
80% of ethanol is made this way
C2H4
+ H2O  C2H5OH
+ Uses renewable resources
+ Continuous process – lots made!
+ Produces no waste products
-Takes longer to produce
- CO2 is given off
- Requires lots of heat and energy
- Relies on a non-renewable resource
USES FOR ETHANOL
H H
H-C-C-O H
H H
• Alcohol
A molecule of ethanol
• Antiseptic wipes
• Perfume
• Rocket Fuel
• Solvents
C1.6 Plant oils and their uses
  
a) Some fruits, seeds and nuts are rich in oils that can be extracted. The plant material is
crushed and the oil removed by pressing or in some cases by distillation. Water and other
impurities are removed.
b) Vegetable oils are important foods and fuels as they provide a lot of energy. They also
provide us with nutrients.
c) Vegetable oils have higher boiling points than water and so can be used to cook foods
at higher temperatures than by boiling. This produces quicker cooking and different
flavours but increases the energy that the food releases when it is eaten.
C1.6.2 Emulsions
  
a) Oils do not dissolve in water. They can be used to produce emulsions. Emulsions are
thicker than oil or water and have many uses that depend on their special properties.
They provide better texture, coating ability and appearance, for example in salad
dressings, ice creams, cosmetics and paints.
b) Emulsifiers have hydrophilic and hydrophobic properties.
C1.6.3 Saturated and unsaturated oils
a) Vegetable oils that are unsaturated contain double carbon–carbon bonds. These can be
detected by reacting with bromine water.
b) Vegetable oils that are unsaturated can be hardened by reacting them with
hydrogen in the presence of a nickel catalyst at about 60 °C. Hydrogen adds to the
carbon–carbon double bonds. The hydrogenated oils have higher melting points so
they are solids at room temperature, making them useful as spreads and in cakes

C1 6.1 EXTRACTING VEGETABLE OIL
There are 2 ways to extract vegetable oils from plants:
1) PRESSING
2) DISTILLATION
1.
2.
3.
4.
5.
1.
2.
3.
Farmers collect seeds from plants
Seeds are crushed and pressed
This extracts oil from them
Impurities are removed
Oil is processed to make it into a
useful product
FOOD AND FUEL
Vegetable oils are important foods:
• Provide important nutrients (e.g. vitamin E)
• Contain lots of energy  so can also be used
as fuels
• Unsaturated oils contain double bonds (C=C)
 they decolourise Bromine water
Plants are put into water and boiled
Oil and water evaporate together
Oil is collected by condensing (cooling
the gas vapours)
Lavender oil is one oil extracted this way
Food
Energy
(kJ)
Veg Oil
3900
Sugar
1700
Meat
1100
Table for info only – don’t
memorise it!
C1 6.2 COOKING WITH VEGETABLE OILS
COOKING IN OIL
•
•
•
•
•
•
Food cooks quicker
Outside becomes crispier
Inside becomes softer
Food absorbs some of the oil
Higher energy content
Too much is unhealthy
Double bonds converted to
single bonds
HARDENING VEGETABLE OILS
• Reacting vegetable oils with HYDROGEN
hardens them  increases melting points
• Makes them solid at room temperature 
makes them into spreads!
+
• Double bonds converted to single bonds
C=C  C-C
• Now called a HYDROGENATED OIL
60oC + Nickel catalyst
• Reaction occurs at 60oC with a nickel
catalyst
C1 6.3 EVERYDAY EMULSIONS
Oils do not dissolve in water
EMULSION EXAMPLES
Emulsion  Where oil and water are
dispersed (spread out) in each
other
1.
2.
3.
4.
5.
 These often have special
properties
Mayonnaise
Milk
Ice cream
Cosmetics – face cream, lipstick etc
Paint
EMULSIFIERS
• Stop water and oil separating out
into layers
Emulsifier
molecule
• Emulsifiers have 2 parts that make
them work:
Oil
droplet
1. Hydrophobic tail – is attracted
to oil
2. Hydrophilic head – is attracted
to water. It has a negative
charge
-
Water
C1.7 Changes in the Earth and its atmosphere
  
a) The Earth consists of a core, mantle and crust, and is surrounded by the
atmosphere.
b) The Earth’s crust and the upper part of the mantle are cracked into a
number of large pieces (tectonic plates).
c) Convection currents within the Earth’s mantle driven by heat released by
natural radioactive processes cause the plates to move at relative speeds of a
few centimetres per year.
d) The movements can be sudden and disastrous. Earthquakes and / or volcanic
eruptions occur at the boundaries between tectonic plates.
C1.7.2 The Earth’s atmosphere
a) For 200 million years, the proportions of different gases in the atmosphere
have been much the same as they are today:
■ about four-fifths (80 %) nitrogen
■ about one-fifth (20%) oxygen
■ small proportions of various other gases, including
carbon dioxide, water vapour and noble gases.
b) During the first billion years of the Earth’s existence there was intense
volcanic activity. This activity released the gases that formed the early
atmosphere and water vapour that condensed to form the oceans.
  
c) There are several theories about how the atmosphere was formed. One
theory suggests that during this period the Earth’s atmosphere was mainly
carbon dioxide and there would have been little or no oxygen gas (like the
atmospheres of Mars and Venus today). There may also have been water vapour
and small proportions of methane and ammonia.
d) There are many theories as to how life was formed billions of years ago.
e) One theory as to how life was formed involves the interaction between
hydrocarbons, ammonia and lightning.
f) Plants and algae produced the oxygen that is now in the atmosphere.
g) Most of the carbon from the carbon dioxide in the air gradually became
locked up in sedimentary rocks as carbonates and fossil fuels.
h) The oceans also act as a reservoir for carbon dioxide but increased amounts
of carbon dioxide absorbed by the oceans has an impact on the marine
environment.
i) Nowadays the release of carbon dioxide by burning fossil fuels increases the
level of carbon dioxide in the atmosphere.
j) Air is a mixture of gases with different boiling points and can be
fractionally distilled to provide a source of raw materials used in a variety
of industrial processes.
C1 7.1 STRUCTURE OF THE EARTH
Atmosphere:
Crust:
Most lies within 10km of the
surface
Solid
Rest is within 100km but it’s hard
to judge!
6km beneath
oceans
35km beneath land
Core:
Made of nickel and iron
Mantle
Outer core is liquid
Behaves like a solid
Inner core is solid
Can flow very slowly
Radius is 3500km
Is about 3000km deep!
C1 7.2 THE RESTLESS EARTH
MOVING CONTINENTS
The Earth’s crust and upper mantle are cracked into a number of
pieces  TECTONIC PLATES
These are constantly moving - just very slowly
Motion is caused by CONVECTION CURRENTS in the mantle,
due to radioactive decay
PANGAEA
If you look at the continents they roughly fit together
Scientists think they were once one large land mass called
pangaea, which then broke off into smaller chunks
PLATE BOUNDARIES
Earthquakes and volcanoes
happen when tectonic plates
meet
These are very difficult to
predict
C1 7.3 THE EARTH’S ATMOSPHERE IN THE PAST
PHASE 1:
Volcanoes = Steam & CO2
• Volcanoes kept erupting
giving out Steam and CO2
• The early atmosphere was
nearly all CO2
• The earth cooled and
water vapour condensed
to form the oceans
PHASE 2:
Green Plants, Bacteria
& Algae = Oxygen
• Green plants, bacteria
and algae ran riot in the
oceans!
• Green plants steadily
converted CO2 into O2
by the process of
photosynthesis
• Nitrogen released by
denitrifying bacteria
• Plants colonise the land.
Oxygen levels steadily
increase
Like
this for
a billion
years!
PHASE 3:
Ozone Layer = Animals
& Us
• The build up of O2
killed off early
organisms - allowing
evolution of complex
organisms
• The O2 created the
Ozone layer (O3) which
blocks harmful UV rays
from the sun
• Virtually no CO2 left
C1 7.4 LIFE ON EARTH
No one can be sure how life on Earth first
started. There are many different theories:
MILLER-UREY EXPERIMENT
•
Compounds for life on Earth came from
reactions involving hydrocarbons (e.g.
methane) and ammonia
•
The energy for this could have been
provided by lightning
OTHER THEORIES
1. Molecules for life (amino acids) came on
meteorites from out of space
2. Actual living organisms themselves arrived
on meteorites
3. Biological molecules were released from
deep ocean vents
The experiment completed
by Miller and Urey
C1 7.5 GASES IN THE ATMOSPHERE
THE ATMOSPHERE TODAY:
CARBON DIOXIDE:
• Taken in by plants during photosynthesis
• When plants and animals die carbon is
transferred to rocks
• Some forms fossil fuels which are
released into the atmosphere when burnt
The main gases in air
can be separated out
by fractional
distillation.
The main gases in the atmosphere today are:
1.
2.
3.
4.
Nitrogen  78%
Oxygen  21%
Argon  0.9%
Carbon Dioxide  0.04%
These gases are
useful in industry
C1 7.6 CARBON DIOXIDE IN THE ATMOSPHERE
The stages in the cycle are shown below:
Carbon moves into and out
of the atmosphere due to
• Plants – photosynthesis &
decay
• Animals – respiration &
decay
• Oceans – store CO2
• Rocks – store CO2 and
release it when burnt
CO2 LEVELS
Have increased in the
atmosphere recently
largely due to the
amount of fossil fuels
we now burn
Definitions
Atom –
Group 0 or 8 are
UNREACTIVE
They have a full outer shell
of electrons
Particles that make up all substances.
Element –
A substance made up of only one kind of atom.
Compound –
Periodic table
arranges elements by
ATOMIC NUMBER
(proton number/the
small one)
A substance made of different types of atoms joined
together.
Mixture –
A substance existing of atoms that can be easily separated
as they are not joined together.
No charge
Max 2 electrons
The number of outer shell electrons match the group the element is found in.
E.g. Lithium 2,1 is a group 1 element.
Max 8 electrons Protons and neutrons
both have a mass of
1
LIMESTONE
E.g. 2,8,8 (Argon)
The number of electrons an
atom has effect the way it
reacts
Covalent Bonding
Non-metals sharing
elections
IONS
Charged particles
H
H C H
H
Ionic Bonding
Lose or gain an
electron
Get a charge +/Attract one another!
Balanced Equations
Used for building
Calcium Carbonate
Limewater
The test for CO2
Ca(OH)2
CaCO3
HEAT
(thermal decomposition)
= CaO
Calcium Oxide
Or Calcium Hydroxide
comes from adding water to CaO
TRANSITION
METALS
Each side should also weigh
the same. Nothing is lost
and nothing extra is made.
Limestone is heated in a
Rotary Lime Kiln
You then have Cement or Mortar
by adding water and sand.
If you add crushed rocks you get
Concrete
A balanced equation has the same number of
atoms of each element on both sides
Using Molecules: In this equation, the large
number in front of the chemical symbol tells use
the molecules needed.
e.g. 1 CH4 molecule reacts with 2 O2 molecules
Metals – Very useful
e.g. Copper wires conduct well Metals which are un-reactive are found in
their NATIVE STATE e.g. GOLD
Most need to be ALLOYED
More reactive metals are found as
to make them harder
METALS ORES and need to be
EXTRACTED
C1
IRON
Pure iron is too soft to be useful.
Adding small amounts of other
elements can improve its properties.
This is ALLOYING.
IRON + ‘other elements’
STEEL
e.g. More easily shaped, harder, resistant to corrosion
VEGETABLE OIL
•Are extracted by
pressing or distillation
•Are high in energy
So useful for cooking
(frying instead of boiling)
You can make
ETHANOL using
ETHENE and
STEAM with a
catalyst
Gives a different flavour, texture
and loads more energy (too
much will make you obese)
•Hydrogen to be
added and break
double bonds
OR
Non-Biodegradable plastics are
BAD!
You can make
ETHANOL using+ CO2
YEAST
enzymes.
(from crude oil)
Products: Alkanes (used for fuel) +
Alkenes (used for plastics, medicines,
dyes and explosives)
They don’t rot away.
Biodegradable plastics will
decompose = less rubbish!
(from plants)
•Made from vegetable oils
Making Plastics:
•Less harmful to environment
Test for double bonds:
•CARBON NEUTRAL
Bromine water (iodine water will also work)
•Lose farming land
Alkenes (with double bonds) go CLEAR!
•Disruption of habitats
Small molecules (monomers) added together
make new long molecules (polymers)
RENEWABLE ENERGY
CRUDE OIL
e.g. ethanol from sugar
A mixture of hydrocarbon compounds
Extracting reactive metals
You might need to smelt or roast
the ore and then use electrolysis
to make it pure
Pure
copper
•Nickel Catalyst
Unsaturated fats are better for you than Saturated fats
-heat them with steam and a catalyst
This helps you decide how to
extract a metal from its ORE.
If its below CARBON it can be
reduced in a BLAST Furnace.
If its a metal above it CARBON
cannot help extract it.
To harden you
will need:
•60oC
High Boiling Point
•Are UNSATURATED
Make big molecules into small ones!
Reactivity Series
making them solid at room temperature for
things like spreads and margarines
•Can be used as fuels
RECYCLINGCRACKING HYDROCARBONS
•Saves energy
•Saves natural
recourses
•Less pollution
Can be HARDENED by adding HYDROGEN
Impure
copper
(copper ore)
Cu 2+
Impurities: include gold and silver
(can be sold)
Electrolysis can be expensive but
will help extract Copper,
Aluminium and Titanium
Very useful and NON-CORROSIVE
(wont rust away)
Make it useful
Hydrogen
and Carbon
ONLY!
FRACTIONAL DISTILLATION
Size effects BOILING POINT
Carbon Dioxide made from burning fuels
is a GREEN HOUSE GAS adding to
GLOBAL WARMING
New polymers are designed to work for
specific jobs. SMART POLYMERS can
change in different temperatures and
light.
We are also able to recycle plastics to
find more uses for them.
Getting clever!
Scientist are using
bacteria and plants
to remove copper
from ores where its
too small to mine.
BIOLEACHING or
PHYTOMINING
Filters and CATALYTIS
CONVERTERS can be fitted to
factories and cars to reduce
pollution
Sulfur impurities also burnt cause …
Alkanes – Saturated hydrocarbons.
No double bonds, Maximum Hydrogen,
Formula: CnH2n+2
High temperatures in
engines can also cause the
nitrogen from the air to form
acids too.
You can also get
PARTICULATES
or Soot!
Bad for you and
the environment
(Global Dimming)
Alkenes – Unsaturated hydrocarbons.
Double bonds, Less Hydrogen
Formula: CnH2n
Burning fuels in plenty of oxygen gives CO2 + H2O
COMPLETE COMBUSTION
Burning without enough oxygen gives CO (carbon monoxide) + H2O
INCOMPLETE COMBUSTION – BAD!
OIL DOES NOT DISSOLVE IN WATER
Wegener’s Big Idea
But they can be spread out in
each other to make an
EMULSION
Adding an EMULSIFIER stops the oil
and water separating – it will also
Food
e.g. Mayonnaise, salad dressings
ice creams
Death &&Decay
improve texture
Emulsions are used in:
•
•
•
Cosmetics
Yummy!
Paints
Experimental Variables
Alfred Wegener
suggested the idea of
continental drift
(moving plates) but
people found it hard to
believe, they couldn’t
see it and had other
ideas like land bridges,
sinking continents and
the crust shrinking.
Also he couldn’t
explain HOW it
worked.
It took fossils and
rocks evidence to
convince people.
Earth Structure
(Solid)
All our resources come
from the crust, oceans
and atmosphere.
Independent Variable – the one
Earths Early
•Formed by volcanoes added CO2,
Atmosphere
I CHANGE
Dependent Variable – the one you
RECORD
Calculating an average
•Which cooled and condensed into
oceans
•Plants then appeared and changes
CO2 to oxygen! (photosynthesis)
Just a
reminder!
Add up all your results
(except any anomalies you are leaving out)
10 + 11 + 12 + 14 = 47
Divide your answer by the number of values you added together.
Here 4 values were used..
So 47
The Primordial soup experiment suggested that life started with a
lightening spark, others suggested a meteorite or the deep ocean
event. Without a time machine we just don’t know what started life
on earth!
4 = 11.75
The Carbon
Cycle
Takes a very
long time!
Death & Decay
The
Problem
area
Death & Decay
Respiration
Respiration of
microorganisms
Carbon in the
atmosphere
has
increased
because we
now burn
more fossil
fuels!
Mostly
oxygen and
nitrogen
Respiration
20%
Burning Fossil
Fuels
Respiration
Returning Carbon to the Atmosphere
The Carbon
cycle: Shows
the movement
of carbon in
and out of the
atmosphere
We don’t know when this will happen so
we cannot predict these events
Gases in the
air can be
separated by
fractional
distillation for
use in industry
Answering Evaluation
questions
You must give a balanced
argument if you can!
2 reasons why you might agree
or think something is good.
2 reasons why you might
disagree or think something is
bad.
Is very quick!
Photosynthesis
When tectonic
plates meet and
collide or rub
against one another
we get natural
disasters
Earths Atmosphere Now
Formation of
Fossil Fuels
Food chain...
Radiation in the mantle causes
CONVECTION CURRENTS
which move the plates
Water and Nitrogen
Control Variables – the ones you KEEP
CONSTANT (the same)
The crust is made up of
tectonic plates which
are always moving..
Very very very .. Slowly.
80%
And a conclusive statement.
(your end opinion)
ALWAYS read the information