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(C3) OCR 21st century GCSE: Chemicals in our Lives

A look at how chemical industry developed in Britain; rocks as raw materials, uses and drawbacks of salt, manufacture of alkalis from salt (uses + environmental impact), neutralisation reactions, and Life Cycle Assessments of industrial processes
by

J Amuah-Fuster

on 8 July 2016

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Transcript of (C3) OCR 21st century GCSE: Chemicals in our Lives

A plasticizer is a chemical which is added to a polymer to increase its flexibility.
Blood pressure
Salt makes the body retain water. This leads to high blood pressure, which causes lots of other problems.
OCR 21st Century GCSE:
C3 - Chemicals in Our Lives

OCR 21st Century GCSE
C3: Chemicals in our Lives
C3.1 - Minerals in Britain
What were the origins of minerals in Britain that contribute to our economic wealth?
C3.2 - Salt
Where does salt come from and why is it so important?
Where does salt come from?
Sources & methods of extraction
Alkalis
Uses, risks and benefits of alkalis
Chlorine
the benefits
Electrolysis
Development of the alkali industry
C3.4 What can we do to make our use of chemicals safe and sustainable?
Risks and benefits
Life Cycle Assessment (LCA)
Outcomes
I understand that a Life Cycle Assessment (LCA) involves consideration of the use of resources including water, the energy input or output, and the environmental impact, of each of these stages:
a. making the material from natural raw materials
b. making the product from the material
c. using the product
d. disposing of the product

When given appropriate information from a Life Cycle Assessment (LCA), I can compare and evaluate the use of different materials for the same purpose.
Outcomes
I understand that there is a large number of industrial chemicals with many widespread uses, including consumer products, for which there is inadequate data to judge whether they are likely to present a risk to the environment and/or human health

I understand that some toxic chemicals cause problems because they persist in the environment, can be carried over large distances, and may accumulate in food and human tissues

I can recall that PVC is a polymer that contains chlorine as well as carbon and hydrogen

I understand that the plasticizers used to modify the properties of PVC can leach out from the plastic into the surroundings where they may have harmful effects
Outcomes
I understand that increased industrialisation led to a shortage of alkali in the nineteenth century

I understand that the first process for manufacturing alkali from salt and limestone using coal as a fuel caused pollution by releasing large volumes of an acid gas (hydrogen chloride) and creating great heaps of waste that slowly released a toxic and foul smelling gas (hydrogen sulfide)

I understand that pollution problems can sometimes be solved by turning wastes into useful chemicals

I understand that oxidation can convert hydrogen chloride to chlorine, and that the properties of a compound are completely different from the elements from which it is made
Alkalis & Acids
Neutralisation reaction equations
What do you know about salt?
Minerals in Britain
Outcomes
I can recall that chlorine is used to kill microorganisms in domestic water supplies and as a bleach

I understand how the introduction of chlorination to treat drinking water made a major contribution to public health

I can interpret data about the effects of polluted water on health and the impact of water treatment with chlorine to control disease

I understand that there may be disadvantages of chlorinating drinking water, including possible health problems from traces of chemicals formed by reaction of chlorine with organic materials in the water
Outcomes
I understand that an electric current can be used to bring about chemical change and make new chemicals through a process called electrolysis

I can recall that chlorine is now obtained by the electrolysis of salt solution (brine)

I can recall examples of important uses by industry of the sodium hydroxide, chlorine and hydrogen produced by electrolysis of brine

I can interpret data about the environmental impact of the large scale electrolysis of brine.
Outcomes
I can recall that, even before industrialisation, alkalis were needed to neutralise acid soils, make chemicals that bind natural dyes to cloth, convert fats and oils into soap and to manufacture glass

I can recall that traditional sources of alkali included burnt wood or stale urine

I understand that alkalis neutralise acids to make salts

I can recall that soluble hydroxides and carbonates are alkalis

I can predict the products of the reactions of soluble hydroxides and carbonates with acids
Outcomes
I understand the importance of salt (sodium chloride) for the food industry, as a source of chemicals and to treat roads in winter

I can recall that salt can be obtained from the sea or from underground salt deposits

I understand how underground salt can be obtained by mining, or by solution in water

I understand why the method used to obtain salt may depend on how the salt is to be used

I understand how the methods of obtaining salt can have an impact on the environment
Outcomes
I understand the advantages of adding salt to food as flavouring and as a preservative

I can recall the health implications of eating too much salt

I can evaluate data related to the content of salt in food and health

I can recall that Government departments, such as the Department of Health and the Department for Environment, Food and Rural Affairs, have a role in:
a) carrying out risk assessments in relation to chemicals in food
b) advising the public in relation to the effect of food on health
Outcomes
I understand how processes such as mountain building, erosion, sedimentation, dissolving and evaporation have led to the formation of valuable resources found in England including coal, limestone and salt

I understand how geologists study sedimentary rocks to find evidence of the conditions under which they were formed, to include:
a. fossils
b. shapes of water borne grains compared to air blown grains
c. presence of shell fragments
d. ripples from sea or river bottom

I understand that chemical industries grow up where resources are available locally, e.g. salt, limestone and coal in north west England
Outcomes
I understand that geologists explain most of the past history of the surface of the Earth in terms of processes than can be observed today

I understand that movements of tectonic plates mean that the parts of ancient continents that now make up Britain have moved over the surface of the Earth

I understand how geologists use magnetic clues in rocks to track the very slow movement of the continents over the surface of the Earth

I understand that the movements of continents means that different rocks in Britain formed in different climates
Geologists can use the Earth’s surface to explain it's history.

Sedimentary rocks contain small grains that are deposited and become cemented together over time.

The shape and size can be compared to tell how the rock was made.
Clues in Rocks
British Minerals
What causes continents to move over the surface of the Earth?

Do the observations of magnetic minerals made by the scientists at Imperial College support or conflict with the theory of plate tectonics?

Suggest evidence that geologists might look for to test the theory that the northern and southern parts of Britain were once on different continents.
The evidence supported continental drift and development of the theory of plate tectonics.
By measuring the angle at which crystals are magnetised in rocks, scientists can work out the latitude at which the rock was originally formed.
The magnetisation line up in the direction of the Earth’s magnetic field at the time. Near the Equator, the magnetisation lies horizontally, nearer to the Poles, the magnetisation is at an angle to the horizontal.
C3 Journey through Time
Understand how Britain came into existence from continental drift.

Understand how Britain has experienced different climates.

Understand how geologists use magnetic clues to track the movement of continents.
The mineral gets its name from magnetic properties of its crystal. Magnetite can be magnetised in a fixed direction once the rock has cooled enough.
Volcanic lava and sediments contain mineral magnetite.
To confirm this scientists used magnetic particles in the rock to track the position of north and south of the Equator.
Magnetic Past
Movements of the
tectonic plates
cause oceans to open up slowly between continents in some parts of the world.
Plate movements bring continents together with great force, creating mountain ranges.
Major volcanic eruptions and earthquakes happen at plate boundaries
.
Which direction does your compass point?

Why do all compasses point this way?

THIS HAS SOMETHING TO DO WITH THE EARTH AND WHAT THE COMPASS IS MADE OF

Is there any way of changing the was a compass points?

USE THE MAGNET PROVIDED TO SHOW WHAT HAPPENS
WHEN YOU GET NEAR TO IT

Are rocks magnetic??
Compasses...what’s the point?
Continental drift
Destructive boundary
The volcanic ash cloud in Iceland ruined flights for months...
Modelling sedimentary rock
Produces red sandstone when deposited via wind and rain.

Produces coal (mainly carbon). Plant matter can be changed into coal if the conditions prevent it rotting.

Produces chalk (calcium carbonate) which is a compound found in bones and shells.

Warm oceans

Desert areas

Swamp areas

Origin of rock
Planet Earth
The
core
is made up of iron and nickel, which helps to create the Earth's
magnetic field
.
At the centre, the core is extremely hot and is made up of a mixture of iron and nickel metals.
Core:
The core is made up of
2 parts
; the
inner
and
outer
core
outer
core is a
molten
mixture of iron and nickel that is moved around by
convection currents
inner
core is
solid
iron and nickel due to
high pressure
.
Mantle
This is made up of very hot
molten
rock that flows very slowly.
Heat from the core creates
convection currents
making the mantle circulate below the crust.
Crust
Also known as the
lithosphere
, this is a thin layer of cold, solid rock 5-30 km thick.
The crust is covered in peaks and troughs (mountains and valleys), with some hollows full of water (seas and oceans).
The crust is not a solid piece of rock, instead, it is broken up into pieces called
plates
.
What is Earth like inside?
Conservative boundary
Pacific plate meets the North American plate.
What happens at Plate Boundaries?
Constructive boundary
The Nazca plate is
moving beneath
the South American plate.
This pushes the continental crust upwards
creating volcanoes
.
School of Rock
In the animation to the left, we are modeling how different types of sedimentary rock can be formed.

The different types of rock shown were
limestone
(from shells and fish bones),
shale
(from mud and silt) &
sandstone
(from sand).
Objectives
Objectives
Sedimentary rocks
can
show

evidence
of the
conditions
under which they formed.
These include;
Fossils
of plants and animals gives clues about
Earth's climate
at the time of death.
Shape

of

water borne

grains
(smooth) compared to
wind blown grains
(sharp)
Presence of
shell fragments
indicate the rock was formed on or around a
coral reef
Ripples
in rock show it came from the
sea

or

river
bottom.
Sources
Health
6 mark question
Choose a brand of food and investigate the levels of salt in their products.

Write a letter to the CEO outlining the levels on salt in their food and why it is important to reduce salt levels.

Examples you could use- Heinz, Kellogg's, Walkers, Nestle, Hovis, McDonalds, or any of the supermarkets' own brands….
Objectives
Relate the advantages and disadvantages of using salt in food.

Understand how to evaluate data related to salt in food.

Recall the role that government departments (department for environment, food and rural affairs) have in the food industry.
Copy this template.
Work in groups to answer the question
Planning your answer
Uses
What do
YOU
know about salt?
Next – Make a group that contains a chef, parent, manufacture and medical professional. Present your ideas to another group.
Your task:

In groups you need to come up with an argument for or against this government policy.

You must decide on:
Name and background of the person
Their opinion
Reasons to back up their opinion
Why salt is needed…
Salt
Health issues associated with salt
Up to 75% of salt intake found already in processed foods.
May increase a person’s blood pressure (hypertension).
Having high blood pressure increases the risk of heart disease and having a stroke.

Vital bodily functions
Agriculture
Industry
Water softening
Road deicing
Why salt is needed…
Salt
Health issues associated with salt
Recommended allowance
We have salt in every cell of our bodies - about 250 grams (a cupful) in an adult human.
Studies have shown that eating too much salt can increase a person’s blood pressure.
Having high blood pressure increases the risk of heart disease and having a stroke.
Stroke
High blood pressure damages arteries in the brain. If these burst, they cause a stroke. This can cause severe brain damage and death.
Heart
Stroke
Blood pressure
Kidneys
Government policies

Where it is found

Uses

DISCUSS what you know about salt?
Related health issues

Heart
High blood pressure makes the heart work harder. Over time this can lead to heart failure or a heart attack. Damage to the arteries that feed the heart can also cause a heart attack.
What would they think? Why?
Parent
Medical professional
Chef
Manufacturer of food products
Imagine that the government has suggested removing salt from all products that it does not naturally occur in.
Kidneys
Kidneys filter excess salt from the blood. Over time, too much salt can cause damage to these essential organs.
Independent task
http://www.nhs.uk/Livewell/Goodfood/Pages/salt.aspx

As a result of the World Health Organisation's guidelines, adults are recommended to take in no more than 6g of salt per day (children under 12 - 4g)
Government role:
Government
Homework
http://www.maldonsalt.co.uk/About-Salt-Where-does-Salt-come-from.html
http://www.maldonsalt.co.uk/About-Salt-The-many-uses-of-Salt.html
Objectives
Understand the importance of salt (sodium chloride) for industry, agriculture and road safety.

Know where and how salt can be obtained (depending on salt use).

Understand the environmental impact of salt extraction methods.
Lets try an exam question
Solution mining
Write a step-by-step guide to solution mining

How are you going to remember the steps?
Solution mining
Ways of obtaining salt
There are 3 ways of obtaining salt that you need to know about.

Underground salt mining
Salt from the sea
Solution mining

Watch the videos about 1 and 2 then fill in the first 2 columns of your sheet
Where does the salt come from?
What are some of the different uses of salt?
Starter
Look at the different examples of salt....
How does their appearance suggest they were obtained by different means?

Could they each be used for the same purposes?
http://www.maldonsalt.co.uk/About-Salt-The-many-uses-of-Salt.html
Road deicing
Water softening
Industry
Agriculture
Vital bodily functions
Taste
Preservative
Solution Mining
This brief click animation should help to explain how solution mining works
What happens to the brine solution to turn it into salt?
Through a combination of
evaporation
and
reduced solubility
, refineries can obtain
pure salt (refined salt)
.
Pure salt can be used in
industy
, such as; making
detergents
and
alkalis
, and
fixing dyes
to textiles.

Refined salt is often used in food to
enhance flavours
and as a
preservative
to keep some foods from spoiling as quickly.
Question Time!
Quiz continued
Calcium carbonate + _______  calcium chloride + carbon dioxide
+ water

sodium carbonate + ______ sodium sulfate + carbon dioxide
+ water

potassium carbonate+ _______  potassium nitrate + carbon dioxide
+ water
What is the acid?


Copper carbonate + ______ copper sulfate + carbon dioxide
+ water

Magnesium carbonate + _______  magnesium chloride + carbon dioxide
+ water

Iron carbonate+ _______  iron nitrate + carbon dioxide + water
 metal carbonate + acid  salt + water + carbon dioxide
1. With hydrochloric acid, metal chloride salts are made
a magnesium carbonate + hydrochloric acid 
b calcium carbonate + hydrochloric acid 
c zinc carbonate+ hydrochloric acid 
 
2. With sulfuric acid, metal sulphate salts are made
a magnesium carbonate + sulphuric acid 
b calcium carbonate + sulfuric acid 
c zinc carbonate + sulfuric acid 
 
3. With nitric acid, metal nitrate salts are made
a calcium carbonate + nitric acid 
b zinc carbonate + nitric acid 
c magnesium carbonate + nitric acid 
Reactions of alkalis
acid + metal hydroxide  salt + water

acid + metal carbonate  salt + carbon dioxide + water
Objectives
give examples of some of the traditional sources of alkalis and what they were used for

recall that soluble hydroxides and carbonates are alkalis

recall that alkalis neutralise acids to make salts

predict the products of the reactions of soluble hydroxides and carbonates with acids
Starter

Make a mind map of all of the uses of alkalis you can think of.

Leave space to add to it throughout the lesson.
Rainbow fizz
Note down your observations

What do your observations tell you?
Equations:

calcium hydroxide + hydrochloric acid 

sodium carbonate + hydrochloric acid 
you MUST wear
eye protection
Practical: Properties of alkalis
Traditional sources of alkalis
Urine (ammonia)
Burnt wood (potash)
paper production
dying fabric
antacid tablets
soap & cleaners
making glass
adjusting soil pH
Some uses of alkalis
Electrolysis will be visited in detail in our next lesson
Next lesson…
Learning Outcomes
Know how alkalis were originally made (E grade)

Explain why we don’t use the original process today (C grade)

Evaluate the process, benefits and risks, and suggest solutions (A grade)
Alkali Act 1863:
Social ideas include;
toxicity & ill health of local workers
bad smell
damage to crops and cattle
lower farmer income
Environmental ideas include;
damage to wildlife habitats
loss of biodiversity
During the industrial revolution (1700s), natural sources of _______ were too scarce to meet demand.
Nicholas Leblanc invented a new process using sulphuric acid, _______ (calcium carbonate), _______ _______ (salt) and coal (carbon) to make _________ _________ on a large scale. (4 marks)

Sodium Chloride Limestone Alkali Sodium Carbonate

How were
limestone
,
salt
and
carbon
obtained for this process? (1 mark)

What were the main benefits for producing alkalis on a large scale? (2 marks)
ANSWERS:
Explain why we don’t still use the LeBlanc process today (C grade)
Activity 1: Making alkali on a large scale
Explain why we don’t still use the LeBlanc process today (C grade)

200,000 TONNES PER YEAR!!
Know why alkalis were originally made (E grade)
Demand:
Manufacture Glass
Specification Links
Understand that:

increased industrialisation led to a shortage of alkali in the 19th century.

the Le Blanc process for mass-production of alkali caused lots of pollution and waste
pollution problems can sometimes be solved by turning wastes into useful chemicals.
24/04/2013

Know why and how alkalis were originally made (E grade)

Explain why we don’t use the original process today (C grade)

Evaluate the process, benefits and risks, and suggest solutions (A grade)
Learning Outcomes
ANSWERS:
Evaluate the process, benefits and risks, and suggest solutions (A grade)
Clearly written answers with a flow in argument should include:

Beneficiaries
: industry, business owners, military, medicine, government (1 mark)
Benefits
: New products, greater wealth, higher standard of living (1 mark)
Victims
: wildlife, local people workers (1 mark)
Costs
: Pollution, environmental degradation, ill-health. (1 mark)
Improvements
:
Cleaner, more sustainable processes developed (1 mark)
Solvay Process (1861) – less waste, more efficient
Brine Electrolysis (industrially by 1892) – all products are useful, cleaner process

Good quality written English with little or no spelling, punctuation or grammar errors (1 mark)
Activity 4:
Evaluate the Le Blanc process (6 marks)
Quality of written communication is vital.
(check spelling, punctuation and grammar)!

Your answer should include:
who benefited and why.
what the costs were and who suffered.
what could be done to improve things.
Evaluate the process, benefits and risks, and suggest solutions (A grade)
A new way… Electrolysis
Use the keyword/phrase cards to create a concept map of how problems produced by the alkali industry may have been tackled.
Activity 3:
Environmental Action!
Alkali Act 1863:
Explain why we don’t still use the LeBlanc process today (C grade)
The Le Blanc Process was
wasteful
:
Low Atom Economy
ANSWERS:
Explain why we don’t still use the LeBlanc process today (C grade)
The Le Blanc Process
Activity 2
What do you think it would be like to live near, and work, in the factory when the Le Blanc process was taking place?
Justify your answers using social and environmental reasons.
During the industrial revolution (1700s), natural sources of
alkali
were too scarce to meet demand.
Nicholas Leblanc invented a new process using sulphuric acid,
limestone
(calcium carbonate),
sodium chloride
(salt) and coal (carbon) to make
sodium carbonate
. (1 mark each)

Limestone, coal and salt could be extracted through
underground mining
and quarrying.
(1 mark)

The alkali industry allowed the UK
boost its economy
through production of
large amounts of soap, glass, and soil neutralisers, as well as alkali itself
(2 marks)
Explain why we don’t still use the LeBlanc process today (C grade)
Explain why we don’t still use the LeBlanc process today (C grade)

1st Prize: Nicolas Le Blanc
Know why alkalis were originally made (E grade)
Exportable Goods
Improve The Economy
Know why alkalis were originally made (E grade)
Demand:
Convert Fats And Oils To Soap
Know why alkalis were originally made (E grade)

Demand:
Fix Dyes To Cloth
Know why alkalis were originally made (E grade)
What is an alkali?
Evaluate the process, benefits and risks, and suggest solutions (A grade)
A new way… the Solvay process (1861)
Explain why we don’t still use the LeBlanc process today (C grade)

Land Pollution
Explain why we don’t still use the LeBlanc process today (C grade)

Water Pollution
Know why alkalis were originally made (E grade)

Demand:
Neutralising Acidic Soil
Know why alkalis were originally made (E grade)

Useful products from alkalis
Demand for alkalis, like sodium carbonate, soared as industrialisation increased in the 19th century.
Know how alkalis were originally made (E grade)

Making alkalis: Fermenting Urine
Know how alkalis were originally made (E grade)

Making alkalis: Dissolving Potash
Evaluate the process, benefits and risks, and suggest solutions (A grade)
Making hydrogen chloride more useful
It was later found that hydrogen chloride could be oxidised to make chlorine, which has different properties.
Hydrogen chloride reacts with oxygen to produce chlorine gas and water.
Where hydrogen chloride can be used as an acid or an additive in making plastics, chlorine has different chemical properties, although it is toxic.
Explain why we don’t still use the LeBlanc process today (C grade)

Air & Water Pollution:
Destroys Habitats, Reduces Biodiversity
Explain why we don’t still use the LeBlanc process today (C grade)

HCl gas

Air Pollution
Explain why we don’t still use the LeBlanc process today (C grade)
Nicolas Le Blanc
b. Dec 6th 1742
d. Jan 16th 1806
Le Blanc Process
How YOU doin’?
Evaluate the process, benefits and risks, and suggest solutions (A grade)

[Oxid]
+
Oxygen
O
Water
2H O
Chlorine
2Cl
Hydrogen chloride
4HCl
Making Chlorine
SODIUM CARBONATE
LIMESTONE
Explain why we don’t still use the LeBlanc process today (C grade)

SULFURIC ACID
COAL
Displacement

[Red.]

H S
800-900◦C

The Le Blanc Process: close-up
Soda Ash was Expensive to import
HCl gas
SODIUM CHLORIDE
(SALT)
2
2
+
2
2
To do:
Explain why each of these could cause a negative impact on the environment.

Currently most of the electricity for the electrolysis of brine is generated using fossil fuels

The electrolysis of brine uses mercury as one of the metals in contact with the solution.
Environmental impact
What goes in? What comes out?

Why do we do electrolysis ?
Uses of the products from the electrolysis of salt

To finish: write a paragraph to go with your diagram which explains what happens during electrolysis
Understand what the ‘electrolysis’ does

Know the products from electrolysis of sodium chloride (salt)
Objectives
An
electric current
can be used to bring about
chemical change
and
make new chemicals
through a process called
electrolysis
.

During electrolysis of
brine
(sodium chloride solution - NaCl) new products are formed.
These are
sodium hydroxide
(NaOH),
chlorine gas
(Cl ) and
hydrogen gas
(H )
Electrolysis
What happens during electrolysis?
One use of salt is in
food
Products from salt
Jot down 5 uses for salt
To answer:

Which

four chemical elements
are present in a solution of sodium chloride in water?

Which products
form as gases
(and are therefore removed from the solution)

What is formed
in solution
as electrolysis takes place?

How does this account for the
change in pH
in the solution?
In went:
Water (H O)
Sodium chloride (NaCl)

Out came:
Sodium hydroxide (NaOH)
Chlorine (Cl )
Hydrogen (H )
sodium hydroxide
– corrosive

chlorine – toxic

Support and clamp the electrolysis cell with a stand and clamp.
To do:
H+

H+
Cl-

Cl-

OR
2
2
Write chemical equations showing what happens at each electrode, indicating which electrode has which charge, and the gases are formed at them.
Write a letter to either;

A developing country explaining why they should chlorinate their water and the benefits it would bring.

Or

David Cameron outlining your concerns about the chlorination of water.
AC3.11.1
Answer the questions about the benefits and risks of chlorinating water
Plenary
Use the computers to research the risks and benefits of chlorinating water
What are the
risks
of chlorinating drinking water?
Identify and weigh up the benefits and risks of the uses of chlorine and chlorine chemicals including the chlorination of water supplies.
Objectives
Starter-
Complete the exam question on Typhoid
Using chlorine chemicals
medicines
pesticides (DDT)
hydrochloric acid
drinking water treatment
bleach and cleaners
Chlorinating drinking water - is it right?
PVC (plastic)
& drawbacks
Which is the acid?
Which is the alkali?
What type of reaction is occurring?
If bubbles are produced, what does this tell you about the product?
Quick Quiz
Exam Questions
Life Cycle Assessment (LCA) involves consideration of the use of resources including water, the energy input or output, and the environmental impact, of each of these stages:
Life Cycle Assessment
Decide whether each card matches cradle, use or grave.

Colour code them!
PVC from cradle to grave
Answers
Outcomes
Manufacturers and importers will pay for most of the cost of REACH. The cost for the whole EU will be about 5 billion Euros over the first 11 years of the testing programme. The EU has a population about 500 million people;

a) Do you think that such a large cost is justified?

b) Is it right that industry should have to organise and pay for the testing? Explain your answer.
Give a chemical example to explain the difference between a hazard and risk.

Why can’t scientists say for sure that small traces of permitted chemicals are completely safe?
Suggest reasons why Stockholm convention allows the use of the insecticide DDT to control mosquitoes in parts of the world where malaria so a serious problem.
Scientists who study toxic chemicals agree that some commonly used synthetic chemicals can be harmful in
large doses
, but
not
in the concentrations found in our bodies.
World Wide Fund for Nature (WWF) and Greenpeace are fearful of synthetic chemicals.
The campaigners have highlighted evidence suggesting that chemicals, such as those found in
plastics
and
pesticides
,
may cause cancer
, or lead to
defects in new-born babies
.
Untested Chemicals
This set of chemicals include;
eight pesticides (DDT and DDE)
two types of compounds used in industry (PCBs)
two by-products of industrial activity (dioxins)
There are synthetic chemicals that
take a long time to break down
. They are classified as persistent organic pollutants (POPs).

Many of these compounds contain
chlorine
. This means they can spread widely around the world in air and water. They build up in the
fatty tissues of animals
.
POPs and Pollution
REACH switches most of the responsibility for control and safety of chemicals from the authorities to the companies that make them, or use them.
Now
industry has to manage the risks
of chemicals for human health and the environment.
In 2007, the EU introduced the REACH system to collect information about the
hazards
of chemicals and to assess the
risks
.
REACH
Starter:

Protecting Health and Environment

LO: to be able to explain why there is a need to check on the safety of a very large number of chemicals, the European Union’s programme for testing and the problem of persistent harmful chemicals

Question Time!
Why is it so hard to prove that there is no risk when people have fears about possible dangers from a chemical?

If alternatives to DEHP became available, how might this affect decisions by hospitals about which material to use?
Benefits and Risks of Plasticisers
LO: to be able to explain the chemical used to plasticise PVC and to be able to explain the risks of PVC and how they are regulated
There is no evidence or known case of anyone ever having been harmed from the use of phthalates.
They are made of small molecules, which can escape from the plastic and dissolve in liquids that are in contact with it. They can also leach out of the plastic used to make blood bags or intravenous drips and so enter patient’s bodies.
Plasticisers are chemicals that make PVC soft and flexible. The most common plasticisers for PVC are phthalates.
Worries of Plasticisers
Why does it makes sense for regulators to ban the use of the DEHP in toys, but only to issue warnings and advice about the use of medical equipment made with PVC softened with the same plasticiser?
PVC with DEHP was used in medical devices. Though it would leach into liquids. There are alternatives but they are expensive.
The EU has restricted two common phthalate plasticisers to toys that cannot be placed in the mouth. A third DEHP has been completely banned.
EU Regulators
stands to rough play
easy to keep clean
can be rigid or flexible
mixed with pigments to give bright colours
Toymakers like to use PVC because it is very versatile:
Toymakers
Starter: what is a plasticiser?
The plasticizer gets between the polymer chains and keeps them further apart, which reduces the forces of attraction between them and makes the material more flexible and softer.
Choose a product that has been designed to reduce its impact on the environment.

Describe the product
Explain how its environmental impact has been reduced.

Give two reasons why it is not a good idea to put products in landfill once we have used them.
Wooden Frame
Plastic Frame
Compare the LCA of wooden window frames against PVC window frames.
An LCA involves collecting data about each stage in the life of the product. It includes the use of materials/water, energy inputs and outputs, and environmental impact.
The aim is to slow the rate at which we use up natural resources that are not renewable. At each stage energy is used.
Manufacturers can assess what happens to he materials in their products. This LCA is part of legislation to protect the environment.
Life Cycle Assessment
What happens to a plastic bottle?
Nan’s TV
Wood – biodegradable so it would rot
Glass, metal and plastics – can last forever, not sustainable (they had a life but not a cycle)
Name 2 uses for chlorine
Name 1 problem with the LeBlanc process
Complete these equations
Name 2 products from the electrolysis of sodium chloride solution?
Name 1 way salt can be extracted from the ground

Name 2 different types of salt
Quiz
What is this called?

What are the risks of this process?
Name 1 food that is high in salt
Starter
a. making the material from natural
raw materials
b. making the product from the
material
c. using the product
d. disposing of the product
Carboniferous rocks
http://www.bbc.co.uk/learningzone/clips/formation-of-carboniferous-limestone/4701.html
http://www.planete-energies.com/en/energy-sources-/coal/the-formation-of-coal-56.html

Which layer went in first?
Which layer went in last?
Which layer is the oldest?
Describe the overall sequence of events.
Magnetisation Magnetic Deduced Cooled

Angle Map Horizontally Direction
6 mark question
Why is it difficult to scientifically investigate the health risks of different levels of salt in the diet?
(1 mark each, for environmental and social effect - max. 2 marks)
The importance of alkalis
Evidence for Conditions
Shell fragments
Grain shape
Fossils
Ripples
All these rocks can be found in the UK.
What do these clues tell us about what the UK was like in the past?
Answers
What
evidence
is there for
where
and
how
rocks are formed?
Question Time
4 marks
Exam Question
4. Fossils
Dinosaur footprints, like these, are found in sedimentary rocks in parts of the UK.
2. Shell fragments
Limestone is being formed today in coral reefs like this one. The limestone evidence shows that parts of the UK were like this during Jurassic times.
1. Ripples
Fossilised ripple marks in ancient sandstone can provide information about the speed and direction of the water when the sand was laid down.
Salt deposits formed from the evaporation of a salt-water lake.
Salt extracted from UK salt mine
Crystallised Evaporated Extracted Sedimentary
Rock salt is a __________ rock formed from salts which have _________out of water as the water has__________. Rock salt is mainly sodium chloride, which can be __________ all year round by mining.

It is beneficial for the UK to have rock salt deposits because we can use it to…..
Rock Salt
Coal seam in the UK
Plants in swamp-like conditions
Carboniferous Plant Sedimentary Swamp
Coal is a ___________ rock that is formed when dead __________ remains are compressed and then covered with soil.

Coal seams were deposited in the UK over 300 million years ago in the __________ period. The coal was made from the remains of trees that grew in __________ like conditions.

It is beneficial for the UK to have rich reserves of coal because…..
Coal
3. Grains
Sandstones are formed in regions that were once deserts. We find sandstone in the UK.
Parts of Britain must have once been
underwater
Britain must have once had a
desert
Britain must have once had
coral reefs
Britain was once inhabited by dinosaurs
How old is it?/When was it made?
Why was it made?What is it used for?
How was it made?
Where would you find it?
What is it?
In pairs; discuss what
questions
you could ask about this object.
Scientific
enquiry
These questions are all useful for scientific enquiry

We can use many of the same enquiry questions to find out about rocks
In your groups…

Write enquiry questions around your rock on the poster paper

Try to answer the questions as best as you can as a group
Rock enquiry
Rock salt
Coal
Limestone
Sedimentary rocks
How
and
where
are different sedimentary rocks formed?
You need to be able to…

Explain how sedimentary rocks,
coal
and
rock salt
are formed

Explain how sedimentary rocks show
evidence
of
where
and
how
they were formed
How and where are different sedimentary rocks formed?
In your groups you will be given a topic and some information about this topic

You need to produce a poster/role play/ demonstrate the process / use the whiteboard to teach the class about your topic
How and where are different sedimentary rocks formed?
Group 1 – Formation of sedimentary rocks

Group 2 – Formation of limestone

Group 3 – Formation of coal

Group 4 – Where is coal formed and why

Group 5 – Formation of rock salt

Group 6 – Where is rock salt formed and why
These can be formed in different environments by different processes.
Limestone
,
coal
and
rock salt
are three important mineral resources in the UK.
limestone
coal
rock salt
Carboniferous
Sedimentary
Plant
Swamp
Crystallised
Sedimentary
Extracted
Evaporated
Pangaea
Solve the puzzle to show how fossils provide
evidence
for continental drift
Plates
move

apart
to form
new rock
Plate
move toward each other
, where the
heavier
plate (oceanic)
sinks beneath
the other (continental).
The
rock is destroyed
as it melts in the mantle.
Plates
slide past
each other, so rock is
neither

created, nor destroyed
.
Friction

between the plates
as they slide can cause
earthquakes
to occur.
QUESTIONS
Earth’s is made up of three main layers.
These plates move around because of very slow convection currents in the underlying semi-solid
mantle
.
High temperatures in the mantle are a by-product of radioactive decay from some of the rocks.
The outer layer is the
crust
, solid rock split into
tectonic plates
.
http://www.absorblearning.com/media/attachment.action?quick=ue&att=2178
Rock salt contains pieces of mud, sand and other minerals, as well as salt.
Therefore, it is useful as a deicer on roads, but not so useful as a food additive nor as a raw material for industry
Sea salt contains dissolved minerals that can be found in the sea. This means there are other elements (potassium, iodine, bromine) to be found aside from sodium and chlorine.
Sea salt
can be eaten
and it even provides minerals we may not get from our diet.
However, sea salt is
not pure enough
to be used in industry
"HCl Gas In Air Is Forbidden"
It took Parliament a
long time
to respond to the demands of the population.

They were weighing up the
risks
of the alkali industry against the
benefits
its brought.
Useful Product
Waste
Suggest how the individual, company or government could tackle some of these problems produced by the alkali industry.

Consider what could be done about:
HCl gas
low amounts of useful materials
effects on people and the environment
Evaluate the process, benefits and risks, and suggest solutions (A grade)
Evaluate the process, benefits and risks, and suggest solutions (A grade)
Discuss
No waste products - all useful products
Answers
sodium (Na), chlorine (Cl), hydrogen (H), and oxygen (O)
Hydrogen (H ) adn Chlorine (Cl ) form as gases.
sodium hydroxide (NaOH) is formed in solution
sodium hydroxide is an alkali and turned the pH paper blue/purple
2
2
2
2
2
Chlorinating drinking water
-
is it

right
? (Risks and Benefits)
What are the
benefits
of chlorinating drinking water?
At a Convention in Stockholm (2001) it was agreed to deal with POPs.
It was made effective in 2004 when 150 countries agreed to outlaw the ‘dirty dozen’.
When is it okay to use DDT?
Underground mining, or
Solution mining
Rock salt,
Sea salt, or
Refined salt
Any of the following:
bread
processed meat (bacon, burgers, ham)
crisps
cheese
chips
Any of the following:
HCl fumes are harmful to workers (breathing) and the environment (form acid rain)
H S released from solid waste is toxic and produces bad smell
Very wasteful process - lots of waste formed to produce a small amount of alkali
HCl pollution may reduce the livelihood of farm workers as they have fewer crops to sell
2
Any 2 of the following:
Bleach
Hydrochloric acid
Treating drinking/waste water
making plastics (PVC)
Any 2 of the following:
Hydrogen,
Chlorine,
Sodium Hydroxide
Solution mining

Holes mean land could collapse.
Damage homes.
Destruction of animal and plant habitats.
hydrochloric + magnesium
acid

sulfuric + potassium
acid hydroxide

nitric + sodium
acid carbonate
magnesium + hydrogen
chloride

potassium + water
sulfate

sodium + carbon + water
nitrate dioxide
Tie-Breaker
In which year was DDT banned?
1972
(closest year wins)
Starter
Suggest reactants that could be used to
make
the following products
calcium sulphate and water
sodium chloride, carbon dioxide and water
lithium nitrate and water
Answers
calcium hydroxide and sulphuric acid
sodium carbona and hydrochloric acid
lithium hydroxide and nitric acid
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