Chemistry-Junior Cycle Science

1. 07/03/2014
Junior Cycle Science
Chemistry
Metals
Theresa Lowry-Lehnen
RGN, BSc (Hon’s) Nursing Science, PGCC, Dip Counselling, Dip Psychotherapy,
BSc (Hon’s) Clinical Science, PGCE (QTS), H. Dip. Ed, MEd
PhD student Health Psychology

2. Periodic table
07/03/2014
The periodic table arranges all the elements
in groups according to their properties.
Vertical
columns are
called GROUPS
Mendeleev
Horizontal rows are called PERIODS

3. 07/03/2014
What does the periodic table tell you?
The SYMBOL of the element
The NAME of the element
The PROTON NUMBER of the element
Au
Gold
79

4. 07/03/2014
Group 1 – The alkali metals
Li
Na
K
Rb
Cs
Fr

5. 07/03/2014
Group 1 – The alkali metals
Some facts…
1) These metals all have to be
stored under ____ because they
react with _______
2) Reactivity increases as you go _______ the group. This is
because the electrons are further away from the _______
every time a _____ is added, so they are given up more easily.
3) They all react with water to form an alkali (hence their
name) and __________, e.g:
Potassium + water
potassium hydroxide + hydrogen
Words – down, oil, shell, hydrogen, nucleus, water

6. The Transition Metals
07/03/2014
Some facts…
1) This section includes metals like gold, mercury, iron, copper
2) They are all ______ and solid (except _________)
3) They are ____ reactive than the alkali metals
4) They can form __________ compounds
Words – hard, coloured, mercury, less

7. Some common symbols…
07/03/2014
Lithium
Li
Copper
Cu
Sodium
Na
Zinc
Zn
Potassium
K
Aluminium
Al
Calcium
Ca
Gold
Au
Magnesium
Mg
Mercury
Hg
Iron
Fe
Fluorine
F
Oxygen
O
Chlorine
Cl
Nitrogen
N
Hydrogen
H
Sulphur
S
Helium
He

8. 07/03/2014
Reactions of metals with oxygen
When a metal reacts with oxygen it will form a METAL
OXIDE. This is what happens when a metal rusts. We can
make this reaction happen quicker by burning the metal.
METAL + OXYGEN
METAL OXIDE
Copy and complete the following reactions:
1) Magnesium + oxygen
2) Copper + oxygen
3) Calcium + oxygen
4) Iron + oxygen

9. 07/03/2014
Reactions of metals with water
When a metal reacts with water hydrogen is always given
off. The other product will be either a metal hydroxide or
a metal oxide.
METAL + WATER
METAL + WATER
METAL OXIDE + HYDROGEN
METAL HYDROXIDE + HYDROGEN
Copy and complete the following reactions:
1) Sodium + water
2) Potassium + water
3) Calcium + water
4) Iron + steam

10. 07/03/2014
Reactions of metals with acids
When a metal reacts with an acid it gives off hydrogen
(which can be “popped” using a lit splint). The other
product is a salt.
METAL + ACID
e.g. magnesium + hydrochloric acid
SALT + HYDROGEN
magnesium chloride + hydrogen
Copy and complete the following reactions:
1) Calcium + hydrochloric acid
2) Zinc + hydrochloric acid
3) Iron + hydrochloric acid
4) Lithium + sulphuric acid

11. 07/03/2014
Complete the following reactions:
1) Lithium + water
Lithium hydroxide + hydrogen
2) Lithium + hydrochloric acid
Lithium chloride + hydrogen
3) Silver + oxygen
Silver oxide
4) Magnesium + sulphuric acid
Magnesium sulphate + hydrogen
5) Potassium + oxygen
Potassium oxide
6) Aluminium + oxygen
Aluminium oxide
7) Manganese + water
Manganese oxide + hydrogen
8) Sodium + sulphuric acid
Sodium sulphate + hydrogen
9) Lithium + oxygen
Lithium oxide
10) Nickel + hydrochloric acid
Nickel chloride + hydrogen

12. 07/03/2014
An example question on reactivity
Metal
A
B
C
D
E
Reaction with
dilute acid
Reaction
with water
Reaction
with oxygen
Some reaction
Slow reaction
Burns brightly
No reaction
No reaction
Reacts slowly
No reaction
No reaction
No reaction
Violent reaction Slow reaction
Burns brightly
Reasonable
reaction
Reacts slowly
Reacts with
steam only

13. The Reactivity Series
07/03/2014
Potassium
Sodium
Calcium
Magnesium
The Reactivity Series lists
metals in order of reactivity:
Aluminium
Carbon
Zinc
Iron
Lead
Copper
Silver
Gold

14. Displacement reactions
07/03/2014
A displacement reaction is one where a MORE REACTIVE metal will
DISPLACE a LESS REACTIVE metal from a compound.
Magnesium
Copper sulphate
Mg
Cu
The magnesium
DISPLACES the copper
from copper sulphate
Mg
SO4
Magnesium sulphate
Cu
Copper
SO4

15. Displacement reactions
07/03/2014
A displacement reaction is one where a MORE REACTIVE
metal will DISPLACE a LESS REACTIVE metal from a
compound.
For example, if you drop some magnesium into copper
sulphate a reaction will happen because magnesium is more
reactive than copper, so the reaction is:
Magnesium + copper sulphate
copper + magnesium sulphate
However, if you drop some copper into magnesium sulphate
NOTHING will happen.

16. 07/03/2014
Some example reactions…
Reaction
Prediction
Observations
Zinc + copper sulphate
Zinc + lead nitrate
Copper + lead nitrate
Copper + silver nitrate
Extension work – write down the equations for these
reactions

17. 07/03/2014
Some example reactions…
Reaction
Prediction
Observations
Zinc + copper sulphate
Reaction DID happen
Zinc + lead nitrate
Reaction DID happen
Copper + lead nitrate
Reaction DID NOT
happen
Copper + silver nitrate
Reaction DID happen
Extension work – write down the equations for these
reactions

18. 07/03/2014
Quiz on acids and alkalis
Acid, alkali or both???
1) This a pH of less than 7
2) This could kill cells
3) A metal hydroxide (e.g. sodium hydroxide) would be an _____
4) When this reacts with a metal hydrogen is released
5) A metal carbonate (e.g. calcium carbonate) would be an _____
6) This would feel soapy on your skin
7) This could be a corrosive
8) This will turn universal indicator purple
9) This would taste sour
10) This means “a base that can be dissolved”

19. Neutralisation reactions
07/03/2014
When acids and alkalis react together they will NEUTRALISE
each other. Neutralisation is an example of a displacement
reaction:
Sodium hydroxide
Na
Hydrochloric acid
H
OH
The sodium DISPLACES
the hydrogen from HCl
Na
Cl
Sodium chloride
H2O
Water
Cl

20. 07/03/2014
Neutralisation experiment
In this experiment we mixed sodium hydroxide (an _____) and
hydrochloric acid together and they ________ each other. The
equation for this reaction is…
Sodium hydroxide + hydrochloric acid
sodium chloride + water
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 to use – nitrate, neutralised, alkali, sulphate, salt, evaporating

21. Making salts
07/03/2014
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
Sodium
hydroxide
Potassium
hydroxide
Calcium
hydroxide
Sulphuric
acid
Nitric acid
Sodium chloride
+ water
Potassium
sulphate + water
Calcium nitrate
+ water

22. 07/03/2014
Salts of transition metals
These are the TRANSITION
METALS – if we make a salt
using a base made from one of
these metals the procedure is
different…
1) Drop the base
into the acid…
2) Filter it to remove
any leftover base
3) Evaporate it
to get the salt

23. Extracting Metals
07/03/2014
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 oxygen. This is called a REDUCTION
reaction.

24. How do we do it?
07/03/2014
Potassium
Sodium
Calcium
Magnesium
Metals ABOVE CARBON, because
of their high reactivity, are
extracted by ELECTROLYSIS
Aluminium
Carbon
Zinc
Iron
Metals BELOW CARBON are
extracted by heating them with
carbon in a BLAST FURNACE
Tin
Lead
Copper
Silver
Gold
Platinum
These LOW REACTIVITY metals
blatantly won’t need to be extracted
because they are SO unreactive you’ll
find them on their own, not in a metal
oxide

25. Extracting metals
07/03/2014
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
High reactivity (i.e
anything above carbon)
Middle reactivity (i.e.
anything below carbon)
Low reactivity
Extraction process
Examples

26. The Blast Furnace
07/03/2014
1) HAEMATITE (iron ore),
limestone and coke (carbon) are
fed in here
2) Hot air is
blasted in
here
3) The carbon reacts with
oxygen from the air to form
carbon dioxide.
4) The carbon dioxide reacts
with more carbon to form
carbon monoxide
6) Molten slag
(waste) is
tapped off here
Iron oxide + carbon monoxide
5) Carbon monoxide reduces
iron oxide to iron. The
molten iron is tapped off here
iron + carbon dioxide

27. Electrolysis
07/03/2014
Molecule of solid
copper chloride
Molecule of solid
copper chloride after
being dissolved
Chloride
ion
Copper
ion

28. Electrolysis
07/03/2014
Electrolysis is used to extract a HIGHLY REACTIVE metal.
When we electrolysed
copper chloride the
negative chloride ions
moved to the positive
electrode and the positive
copper ions moved to the
negative electrode –
OPPOSITES ATTRACT!!!
= chloride ion
= copper ion

29. Redox reactions
07/03/2014
These happen during electrolysis:
At the positive electrode the
negative ions LOSE electrons to
become neutral – this is
OXIDATION
At the negative electrode the
positive ions GAIN electrons to
become neutral – this is
REDUCTION
These two processes are
called REDOX REACTIONS
OILRIG –
Oxidation Is Loss of electrons
Reduction Is Gain of electrons

30. 07/03/2014
Purifying
Aluminium
Aluminium has to be extracted from its ore (called ________) by
electrolysis. This is because aluminium is very ___________. The ore
is mixed with cryolite to lower its ________ ________. The ore is
then melted so that the ions can ______. The positively charged
aluminium ions gather at the ___________ electrode. Oxygen forms
at the positive electrode and causes it to wear away, which means that
they have to be __________ frequently.
Words – melting point, replaced, negative, bauxite, reactive, move

31. Rusting Experiment
RUST
NO RUST –
no water
07/03/2014
NO RUST –
no oxygen

32. Rusting
07/03/2014
Rust is formed when iron reacts with water AND oxygen.
It’s an example of an oxidation reaction which can be
sped up using salt. There are several ways of dealing
with rust:
1) Regular painting or oiling
2) Galvanising – this is when iron objects are coated with
zinc
3) Making objects out of a non-rusting metal, such as
stainless steel
4) Attaching zinc bars to ships – the water will react
with the zinc before it reacts with the iron, because
zinc is more reactive