1. REACTIVITY SERIES

2. Metals and water

3. Metals and water
The Romans used lead to make water pipes but didn’t know that lead reacts slowly with water and makes it poisonous!
Some metals react vigorously with water, some metals react slowly and some do not react at all.
What is the best type of metal to use for water pipes?

4. Metals and water – general equation
Potassium and sodium are metals that react vigorously with water even when a small amount of each metal is used.
When a metal reacts with water, the products are a metal hydroxide and hydrogen gas. What is the general equation for the reaction of a metal with water?
metal
water
metal hydroxide
hydrogen
What is the test that a metal hydroxide is produced?

5. Metals and water – equations
What are the products when each metal reacts with water?
What is the balanced symbol equation for each reaction? 
water +
lithium
lithium hydroxide +
hydrogen
2Li +
2H2O 
2LiOH H2 
water +
sodium
sodium hydroxide +
hydrogen
2Na +
2H2O 
2NaOH H2 
water +
potassium
potassium hydroxide +
hydrogen 2K +
2H2O 
2KOH H2

6. Metals and water – observations
James investigated how reactive some metals are when they react with water and made these observations.
Potassium immediately produces a lilac flame as it skims around the surface making a fizzing noise.
potassium
The sodium melts and skims over the surface producing a stream of small bubbles. Sometimes a yellow-orange flame appeared.
sodium
Bubbles of gas are given off quite quickly. When tested with universal indicator the water is now alkaline.
lithium
Metal Reaction with water
Which of these metals is the most reactive with water?
Which of these metals is the least reactive with water?

7. Metals and water – more observations
James investigated how reactive other metals are with water and made these observations.
No reaction.
silver
copper
Reacts slowly with cold water but reacts quickly with steam.
magnesium
gold
Metal Reaction with water
Copper is used in plumbing and silver and gold in jewellery.
Why are these unreactive metals suitable for such uses?

8. Metals and water – using unreactive metals
The words “plumber” and “plumbing” come from plumbum (the Latin word for lead) because the ancient Romans used lead for their water pipes.
Lead reacts very slowly with water making it poisonous, so this metal is no longer used in plumbing.
Copper is a much better metal for water pipes because it does not react at all with water – plumbers should be renamed coppers!

9. Metals and water – order of reactivity
Put the following metals in order of reactivity based on their reaction with water, starting with the most reactive:
copper, gold, magnesium, lithium, potassium, silver, sodium.
potassium
sodium
lithium
magnesium
copper, silver, gold

10. Metals and oxygen

11. Metals and oxygen – general equation
Most metals will react with oxygen. Some metals react faster than others and some may react very slowly or not at all.
Magnesium, for example, burns in oxygen with a bright flame.
The magnesium reacts with oxygen to produce magnesium oxide.
When a metal does react with oxygen, the product is a metal oxide. What is the general equation for the reaction of a metal with oxygen?
metal
oxygen
metal oxide

12. Metals and oxygen – equations
What are the products when each metal reacts with oxygen?
What is the balanced symbol equation for each reaction? 
oxygen +
magnesium
magnesium oxide
2Mg + O2 
2MgO 
oxygen +
copper
copper oxide
2Cu + O2 
2CuO 
oxygen +
iron
iron oxide
4Fe +
3O2 
2Fe2O3

13. Metals and oxygen – observations
Shaida investigated how reactive some metals are when they react with oxygen and made these observations.
The iron filings glowed red and sparkled leaving a brown-black looking solid.
iron
The copper turnings went through reds and oranges and then slowly got a permanent coating of black.
copper
The ribbon burned with a dazzling white flame giving grey-white smoke and ash.
magnesium
Metal Reaction with oxygen
Which of these metals is the most reactive with oxygen?
Which of these metals is the least reactive with oxygen?

14. Metals and oxygen – order of reactivity
Put the following metals in order of reactivity based on their reaction with oxygen, starting with the most reactive:
copper, iron, magnesium.
magnesium
iron
copper

15. Metals and acid

16. Metals and acid – the acid test
The first scientists to study chemistry were called alchemists. They were interested in many things including finding ways of changing cheap metals into gold. Some were very good at making metals look gold.
Acid was used to find out if gold objects were made of real or fake gold. Most metals react with strong acids. Gold is such an unreactive metal that it does not react with strong acids.
This became known as “the acid test” because it stopped tricksters making false claims that something was gold.
The phrase “the acid test” is used today to mean any process that will reveal fakes.

17. Metals and acid – experiment

18. Metals and acid – general equation
Gold is an unreactive metal that does not react with acid.
Other metals, such as magnesium and zinc, react with acid producing bubbles of gas.
The “squeaky pop” test shows that this gas is hydrogen.
When a metal reacts with acid, the products are a metal salt and hydrogen. What is the general equation for the reaction of a metal with acid?
metal
acid
metal salt
hydrogen
How does the type of acid affect the type of salt produced?

19. Metals and hydrochloric acid – equations
What is made when each metal reacts with hydrochloric acid?
What is the balanced symbol equation for each reaction? 
hydrochloric acid +
magnesium
magnesium chloride +
hydrogen Mg +
2HCl 
MgCl2 H2 
hydrochloric acid +
aluminium
aluminium chloride +
hydrogen
2Al +
6HCl 
2AlCl3
3H2 
hydrochloric acid +
zinc
zinc chloride +
hydrogen Zn +
2HCl 
ZnCl2 H2

20. Metals and sulfuric acid – equations
What is made when each metal reacts with sulfuric acid?
What is the balanced symbol equation for each reaction? 
sulfuric acid +
magnesium
magnesium sulfate +
hydrogen Mg +
H2SO4 
MgSO4 H2 
sulfuric acid +
aluminium
aluminium sulfate +
hydrogen
2Al +
3H2SO4 
Al2(SO4)3
3H2 
sulfuric acid +
zinc
zinc
sulfate +
hydrogen Zn +
H2SO4 
ZnSO4 H2

21. Metals and nitric acid – equations
What is made when each metal reacts with nitric acid?
What is the balanced symbol equation for each reaction? 
nitric acid +
magnesium
magnesium nitrate +
hydrogen Mg +
2HNO3 
Mg(NO3)2 H2 
nitric acid +
aluminium
aluminium nitrate +
hydrogen
2Al +
6HNO3 
2Al(NO3)3
3H2 
nitric acid +
zinc
zinc nitrate +
hydrogen Zn +
2HNO3 
Zn(NO3)2 H2

22. Metals and acid – observations
Greg investigated how reactive some metals are with hot and cold acid and made these observations.
Metal
Reaction with cold acid (HCl)
Reaction with
hot acid (HCl)
magnesium
Fizzed rapidly -
aluminium
Bubbled quickly
copper
No reaction
iron
Slow bubbling
lead
Occasional bubble
calcium
Really fast
zinc
Moderate bubbling
Which of these metals is the most reactive with acid?
Which of these metals is the least reactive with acid?

23. Metals and acid – order of reactivity
Put the following metals in order of reactivity based on their reaction with acid, starting with the most reactive:
aluminium, calcium, copper, iron, lead, magnesium, zinc.
calcium
magnesium
aluminium
zinc
iron
lead
copper

24. Metals and acid – reactivity activity

25. Reactivity series and displacement

26. Comparing orders of reactivity
When the orders of reactivity of metals with water, oxygen and air are compared, there is a pattern of results.
with water
potassium
sodium
lithium
magnesium
copper
silver
gold
with oxygen
magnesium
iron
copper
with acid
calcium
magnesium
aluminium
zinc
iron
lead
copper
Combining the information from all the reactions of metals with water, oxygen and air gives an overall order of reactivity
called the reactivity series.

27. increasing reactivity
The reactivity series
The reactivity series is the list of metals placed in order of their reactivity.
One way to remember this order is to learn this silly sentence:
potassium
sodium
calcium
magnesium
aluminium
zinc
iron
lead
copper
silver
gold
Please
send
Charlie’s
monkeys
and
zebras in
lead
cages
securely
guarded!
increasing reactivity

28. What is the order of metals?

29. Using the reactivity series
The reactivity series can be used to make predictions about the reactions of metals.
Predictions can be made about simple reactions of metals with oxygen, water and acids.
Predictions can also be made about more complex reactions where one metal is competing with another.
potassium
sodium
calcium
magnesium
aluminium
zinc
iron
lead
copper
silver
gold
increasing reactivity

30. Simple reactions – predictions
Use the reactivity series to predict if a reaction will take place and how intense the reaction will be.
Metal
React with
Prediction
gold
acid
calcium
water
sodium
oxygen
silver
zinc
potassium
sodium
calcium
magnesium
aluminium
zinc
iron
lead
copper
silver
gold
no reaction
fizzing
burns vigorously
very slow reaction
burns moderately

31. When does displacement happen?
The reactivity series can be used to predict if a metal will react with a metal compound (e.g. chloride, nitrate or sulfate).
If the metal is more reactive than the metal in the compound,
it competes with the less reactive metal.  +
less reactive metal compound
more reactive metal +
less reactive metal
more reactive metal compound
The more reactive metal pushes out, or displaces, the less reactive metal from its compound.
If the metal is less reactive than the metal in the compound,
it will not compete and so there is no reaction. +
no reaction 
more reactive metal compound
less reactive metal

32. Displacement reactions – examples
The reactivity series can be used to predict if a metal will react with a metal compound.
Will magnesium react with copper chloride? 
copper chloride +
magnesium
copper +
magnesium chloride
Magnesium is a more reactive metal than copper, so magnesium displaces the copper from its compound.
Will silver react with magnesium chloride? 
magnesium chloride +
silver
no reaction
Silver is a less reactive metal than magnesium, so silver does not displace the magnesium from its compound.

33. Displacement reactions – observation
This photograph shows what happens when magnesium reacts with copper sulfate.
Why does the blue colour of the coppers sulfate solution gradually disappear during this reaction?
before
after
copper +
magnesium sulfate 
copper sulfate
magnesium
Magnesium is a more reactive metal than copper and so the magnesium displaces the copper from the copper sulfate solution. This is why the blue colour disappears.

34. Displacement of sulfates – predictions
Use the reactivity series to predict if there is a reaction when these metals are added to different metal sulfate solutions.
magnesium sulfate
zinc
sulfate
iron
copper sulfate
magnesium
copper
metal sulfate
solution
metal             
= displacement reaction
= no reaction 

35. Displacement of sulfates – magnesium
Does magnesium react with and displace these metal sulfates and if so what products are formed? 
copper sulfate +
magnesium
magnesium sulfate +
copper  Mg +
CuSO4 
MgSO4 Cu 
zinc
sulfate +
magnesium
magnesium sulfate +
zinc  Mg +
ZnSO4 
MgSO4 Zn 
iron
sulfate +
magnesium
magnesium sulfate +
iron  Mg +
FeSO4 
MgSO4 Fe

36. Displacement of sulfates – zinc
Does zinc react with and displace these metal sulfates and if so what products are formed?  
magnesium sulfate +
zinc
no reaction 
iron
sulfate +
zinc
zinc
sulfate +
iron  Zn +
FeSO4 
ZnSO4 Fe 
copper sulfate +
zinc
zinc
sulfate +
copper  Zn +
CuSO4 
ZnSO4 Cu

37. Displacement of sulfates – iron
Does iron react with and displace these metal sulfates and if so what products are formed?  
magnesium sulfate +
iron
no reaction  
zinc
sulfate +
iron
no reaction 
copper sulfate +
iron
iron
sulfate +
copper  Fe +
CuSO4 
FeSO4 Cu

38. Displacement of sulfates – copper
Does copper react with and displace these metal sulfates and if so what products are formed?  
magnesium sulfate +
copper
no reaction  
zinc
sulfate +
copper
no reaction  
copper sulfate +
copper
no reaction

39. Displacement of oxides
Displacement reactions can also occur between a metal and a metal compound that is a solid. 
iron
oxide +
aluminium
iron +
aluminium oxide
The more reactive aluminium wins the oxygen from the less reactive iron. The reaction gets so hot that the iron melts!
This is the Thermit reaction and is used to weld railway lines.

40. Displacement of oxides – predictions
Use the reactivity series to predict if there is a reaction when each mixture of a metal and a metal oxide is heated.
zinc
oxide
iron
copper oxide
copper
metal
oxide
metal       
= displacement reaction
= no reaction 

41. Displacement of oxides – zinc
Does zinc react with and displace these metal oxides and if so what products are formed? 
copper oxide +
zinc
zinc oxide +
copper  Zn +
CuO 
ZnO Cu 
iron oxide +
zinc
zinc oxide +
iron 
3Zn +
2Fe2O3 
3ZnO
2Fe
Zinc is the more reactive than copper and iron.

42. Displacement of oxides – iron
Does iron react with and displace these metal oxides and if so what products are formed?  
zinc oxide +
iron
no reaction 
copper oxide +
iron
iron oxide +
copper 
2Fe +
3CuO 
Fe2O3
3Cu
Iron is less reactive than zinc but more reactive than copper.

43. Displacement of oxides – copper
Does copper react with and displace these metal oxides and if so what products are formed?  
zinc oxide +
copper
no reaction  
iron oxide +
copper
no reaction
Copper is less reactive than zinc and iron and will not displace either of these metals.

44. Displacement reactions – activity
Use the reactivity series to predict if each mixture will react.
Reactants
Reaction?
iron oxide
magnesium
potassium
sodium
calcium
magnesium
aluminium
zinc
iron
lead
copper
silver
gold 
copper sulfate
zinc 
potassium
hydrochloric acid  
gold
iron chloride 
calcium
sodium chloride
calcium
oxygen 

45. Displacement reactions – activity
Use the reactivity series to predict if each mixture will react and complete the word equation. 
aluminium oxide +
magnesium
magnesium oxide +
aluminium 
iron chloride +
magnesium
magnesium chloride +
iron 
zinc oxide +
silver
no reaction 
gold nitrate +
copper
copper nitrate +
gold

46. Contents
Summary activities

47. reactive – A substance that reacts quickly or easily.
Glossary
displaced metal – The metal that is pushed out of a compound by a more reactive metal.
displacement – A reaction in which a more reactive metal replaces a less reactive metal in a compound.
reactive – A substance that reacts quickly or easily.
reactivity – How quickly or easily a substance will react.
reactivity series – The list of metals placed in order of their reactivity starting with the most reactive.
tarnished – A metal that has become dull after reacting with water and oxygen in the air.
Thermit reaction – The displacement reaction between aluminium and iron oxide that is used to weld railway lines.
unreactive – A substance that reacts very slowly or
does not react at all.

48. True or false?