C1.18a Is oxygen needed for iron to corrode? Name
Class
Date
The corrosion of iron is called rusting. Water is needed for iron to corrode. In this experiment you are going to find out if oxygen is also needed for iron to corrode.
Apparatus
Health and safety
conical flask
gauze
Bunsen burner
●
Wear eye protection
2 boiling tubes
2 iron nails
oil
●
Take care with hot apparatus
boiling-tube rack
mat
Method A Boil some water in a conical flask for 3 minutes. This removes all the dissolved oxygen from the water. B Once the flask is cool enough, half-fill one boiling tube with the boiled water and put a nail in the tube. C Put a layer of oil on top of the boiled water in the boiling tube. D Set up a similar boiling tube with tap water and a nail. E Leave both tubes for a few days and compare them to see if the iron oil corrodes.
Recording your results 1
Describe the results you got for each tube. Tube with boiled water: Tube with tap water:
Considering your results/conclusions 2
Explain what your results tell you about the corrosion of iron.
3
Is iron oxidised or reduced when it corrodes?
4
Why was the water boiled?
5
What was the oil for?
6
What was done to ensure that this experiment was a fair test?
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
tap water
boiled water
C1.18b Oxidation and reduction Name
Class
Date
In each of the following reactions, decide whether the substance shown in bold is oxidised or reduced. 1
aluminium oxide → aluminium + oxygen
2
nickel + oxygen → nickel oxide
3
carbon + zinc oxide → carbon dioxide + zinc
4
iron oxide + hydrogen → iron + water
5
aluminium + chromium oxide → aluminium oxide + chromium __________________
6
aluminium + oxygen → aluminium oxide
7
hydrogen + copper oxide → copper + water
8
calcium oxide → calcium + oxygen
9
tungsten oxide + hydrogen → tungsten + water
10 magnesium + iron oxide → magnesium oxide + iron
C1.18b Oxidation and reduction Name
Class
Date
In each of the following reactions, decide whether the substance shown in bold is oxidised or reduced. 1
aluminium oxide → aluminium + oxygen
2
nickel + oxygen → nickel oxide
3
carbon + zinc oxide → carbon dioxide + zinc
4
iron oxide + hydrogen → iron + water
5
aluminium + chromium oxide → aluminium oxide + chromium __________________
6
aluminium + oxygen → aluminium oxide
7
hydrogen + copper oxide → copper + water
8
calcium oxide → calcium + oxygen
9
tungsten oxide + hydrogen → tungsten + water
10 magnesium + iron oxide → magnesium oxide + iron
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.18c The extraction of metals The table shows part of the reactivity series of metals: most reactive
least reactive
potassium sodium calcium magnesium aluminium zinc iron nickel lead copper silver gold
1
Metals are extracted from ores. What is an ore?
2
Metals are usually extracted by heating them with carbon or by electrolysis. Predict which method is used to extract each of the following metals: a
magnesium
b lead c
gold
3
The extraction of metals involves reduction. Explain why.
4
Iron could be extracted from iron oxide by electrolysis or heating with carbon. Why is heating with carbon the preferred method?
5
Write word equations for the following extractions. a
extraction of calcium from calcium oxide by electrolysis
b extraction of zinc from zinc oxide by heating with carbon. 6
Say which substance is reduced in each of the reactions in question 5, and explain your answers.
Extra challenge 7
Write balanced equations for the reactions in question 5. The formula for calcium oxide is CaO and for zinc oxide is ZnO.
Š Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.18d Oxidation and reduction Name
Class
Date
Oxidation is the addition of oxygen. Some metals can be oxidised on reaction with oxygen. How they react with oxygen is linked to their position in the Reactivity Series. Reduction is the loss of oxygen, and metals are extracted by reduction of their oxides.
Apparatus
Health and safety
iron wool
magnesium ribbon FLAMMABLE
●
Wear eye protection
copper foil
tongs
●
Take care with hot apparatus
Bunsen burner
heat-resistant mat
●
ceramic paper
zinc powder FLAMMABLE
Do not look directly at magnesium when it reacts
●
Copper oxide is harmful.
●
Zinc and magnesium are highly flammable.
copper oxide HARMFUL wooden splint (spatula)
Method Oxidation reactions
A Hold a piece of iron wool with tongs in a Bunsen flame on a heatproof mat. Record what happens. B Repeat with pieces of magnesium and copper. Reduction reactions C Place a small amount of zinc powder with a small amount of copper oxide on a piece of ceramic paper and mix the two substances together with a wooden splint. D Place the ceramic paper on a heatproof mat and heat from above with a Bunsen burner. Record what happens. E Your teacher may show you a similar reaction between aluminium and iron oxide, called the thermite reaction.
Recording your results 1
Record your observations in a suitable table.
Considering your results/conclusions 2
3
a
What is an oxidation reaction?
b
Which metals reacted with oxygen?
c
Write word equations for any reactions that took place.
d
Which metals burned in oxygen?
e
What is the link between the Reactivity Series and how the metal reacts with oxygen?
a
What is a reduction reaction?
b
Write word equations for any reduction reactions that took place.
c
In each case, state which substance was reduced.
d
In each case, explain why the reaction took place in terms of the Reactivity Series.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.