Making Changes

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Making Changes
(Edexcel)
W Richards The Weald School
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Reactivity Practical
Task to place six metals in order of reactivity
Equipment hydrochloric acid, calcium, copper,
iron, aluminium, magnesium, zinc
Conclusion I think the order of reactivity is
Calcium Magnesium Aluminium Zinc Iron Copper
The actual order of reactivity is
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The Reactivity Series
Potassium Sodium Calcium Magnesium Aluminium Carbo
n Zinc Iron Lead Copper Silver Gold
The Reactivity Series lists metals in order of
reactivity
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An example question on reactivity
Metal Reaction with dilute acid Reaction with water Reaction with oxygen
A Some reaction Slow reaction Burns brightly
B No reaction No reaction Reacts slowly
C No reaction No reaction No reaction
D Violent reaction Slow reaction Burns brightly
E Reasonable reaction Reacts with steam only Reacts slowly
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Extracting Metals
Some definitions
A METAL ORE is a mineral or mixture of minerals
from which it is economically viable to extract
some metal.
Most ores contain METAL OXIDES (e.g. rust iron
oxide).
To extract a metal from a metal oxide we need
to REDUCE the iron oxide. This is called a
REDUCTION reaction. To put it simply
Iron ore
Reduce the iron oxide to make iron
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How do we do it?
Potassium Sodium Calcium Magnesium Aluminium Carbo
n Zinc Iron Tin Lead Copper Silver Gold Platinum
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Extracting metals

1. What is an ore?
2. In what form are metals usually found in the
   Earth?
3. How do you get a metal out of a metal oxide?
4. What is this type of reaction called?

Type of metal Extraction process Examples
High reactivity (i.e anything above carbon)
Middle reactivity (i.e. anything below carbon)
Low reactivity
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Reducation and Oxidation
Some examples of reduction
An example of oxidation
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Neutralisation reactions
When acids and alkalis react together they will
NEUTRALISE each other
Sodium hydroxide
Hydrochloric acid
OH
Cl
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Neutralisation experiment
In this experiment we mixed sodium hydroxide (an
_____) and hydrochloric acid together and they
________ each other. The equation for this
reaction is

• A ____ was formed during the reaction, and we
  could have separated this by __________ the
  solution. The salt that we formed depended on
  the acid
• Hydrochloric acid will make a CHLORIDE
• Nitric acid will make a _________
• Sulphuric acid will make a _________

Words nitrate, neutralised, alkali, sulphate,
salt, evaporating
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Making salts
Whenever an acid and alkali neutralise each other
we are left with a salt, like a chloride or a
sulphate. Complete the following table
Hydrochloric acid Sulphuric acid Nitric acid
Sodium hydroxide Sodium chloride water
Potassium hydroxide Potassium sulphate water
Calcium hydroxide Calcium nitrate water
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Using different bases
A metal oxide base
A metal carbonate base
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Reactions of metals carbonates with acid
A metal carbonate is a compound containing a
metal, carbon and oxygen.
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Reactions of metal oxides with acid
A metal oxide is a compound containing a metal
and oxide. They are sometimes called BASES. For
example
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Neutralisation reactions
A neutralisation reaction occurs when an acid
reacts with an alkali. An alkali is a metal
oxide or metal hydroxide dissolved in water.
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Uses of salts
Whats the point in making salts like calcium
sulphate? They have many uses, including

• As fertilisers, e.g. Ammonium nitrate
• In fireworks, e.g. Barium salts produce green
  colours
• In colouring glass, e.g. Copper salts produce
  turquoise glass
• As fuel additives to reduce pollution

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Hazard signs to learn
Acid
Corrosive
Toxic
Harmful
Irritant
Oxidising
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The Chemistry of Cooking
Research task
Find out what happens to chemicals when food is
cooked, for example

1. Why does meat go brown when it is cooked?
2. What happens when food goes bad?
3. What causes bread and cakes to rise?
4. What foods can cause hyperactivity?

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Thermal decomposition
Thermal Decomposition is when a substance breaks
down into a simpler substance through the action
of heat. For example, consider copper carbonate
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Reactions with water
When blue copper sulphate crystals are heated
they break down into anhydrous copper sulphate, a
white powder. This can be reversed

1. Heat the hydrated copper sulphate
2. Remove the heat and add water

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Collecting Gases

1. Use this method if the gas is heavier than air
   (e.g. CO2, Cl2)

2) Use this method if the gas is lighter than
air (e.g. NH3, H2)

1. Use this method if the gas doesnt dissolve in
   water (e.g. CO2, O2, H2)

4) Use this method if you want to measure the
volume of gas
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Testing for Hydrogen
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Testing for Carbon Dioxide
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Testing for Chlorine
Chlorine bleaches damp indicator paper
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Testing for Oxygen
Oxygen will relight a glowing splint
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Testing for Ammonia
Ammonia will turn damp indicator paper blue
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Some common chemicals and their uses
Fizzy drinks, baking, fire extinguishers,
aerosols Lubricants, future energy production,
living! Production of other chemicals,
digestion Fertilisers, bleaches, dyes and
oils/fats Soft drinks and laxatives Manufacture
of paper, textiles, soaps and detergents Seasoning
for foods, preservative Cleaning and
rust-proofing, acidifying jellies and drinks Food
preservative, condiment Fats, plastics,
photographic film, emulsions and adhesives
Sodium hydroxide (caustic soda) Citric
acid Ammonia Carbohydrates Carbon
dioxide Water Hydrochloric acid Phosphoric
acid Sodium chloride Ethanoic acid (acetic acid)