CIE IGCSE Chemistry

Topic Questions

9.2 Reactivity Series & Corrosion of Metals

1a1 mark

A reactivity series of metals is given below.

  Metal name  Symbol 
Most reactive  Sodium Na
  Lithium Li
  Magnesium  Mg
  Zinc Zn
  Manganese Mn
  Iron Fe
  Copper  Cu
Least reactive  Rhodium  Rh

Which two metals will react most vigorously with cold water?

1b1 mark

Which two metals will not react with dilute hydrochloric acid?

1c1 mark

Extended Only

Deduce the formula of iron(III) sulfate.

1d1 mark

What is the formula of a magnesium ion? 

1e3 marks

Describe a test-tube experiment which will show that manganese is more reactive than copper.

1f5 marks

Manganese is a typical transition metal.

Predict three physical and two chemical properties of this metal.

Physical properties

Chemical properties 

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2a2 marks

Reactive metals tend to have unreactive compounds. The following is part of the reactivity series.

Sodium  Most reactive 
Calcium  
Zinc  
Copper   
Silver  Least reactive 

Sodium hydroxide and sodium carbonate do not decompose when heated. The corresponding calcium compounds do decompose when heated. Complete the following equations.

Calcium carbonate → ................... ...................... + .................. ......................


Ca(OH)2 → ................ + ................ 

2b1 mark

Which of the metals in the list have oxides which are not reduced by carbon?

2c
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2 marks

Choose from the list metals whose ions would react with zinc.

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3a2 marks

Table 1.1 compares the reactivity of cobalt with that of three other metals.

Table 1.1

metal reactivity with cold water reactivity with steam
barium reacts rapidly  
cobalt no reaction reacts slowly when heated
magnesium reacts very slowly reacts rapidly
zinc no reaction reacts easily when heated


Use this information to put the four metals in order of their reactivity. Put the least reactive metal first.

Ywl1Im4h_q3ci_specimen-paper-0620-03-cie-igcse-chemistry

3b1 mark

Extended Only

Copper metal is obtained when scrap iron is added to aqueous copper(II) sulfate.

The reaction between iron and aqueous copper(II) sulfate is a displacement reaction.

State why this displacement reaction takes place.

3c1 mark

Extended Only

Write a symbol equation for the reaction between iron and aqueous copper(II) sulfate.

3d1 mark

A displacement reaction is one method for obtaining copper metal from aqueous copper(II) sulfate.


Identify another method for obtaining copper metal from aqueous copper(II) sulfate.

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4a2 marks

Many compounds have important uses.

The table compares the reactions of four metals with steam.

metal reaction with steam
copper does not react
magnesium reacts rapidly
sodium reacts explosively
zinc reacts slowly when warmed

Put the four metals in order of their reactivity.

Put the least reactive metal first.

q3b_0620-s20-qp-32_cie-igcse-chemistry

4b2 marks

Rust contains hydrated iron(III) oxide.


Describe and explain one method of preventing iron from rusting.

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5a2 marks

The table shows some observations about the reactivity of four metals with dilute sulfuric acid.

metal reaction with sulfuric acid
iron a slow stream of bubbles is seen
magnesium a rapid stream of bubbles is seen
nickel a few bubbles slowly form
tungsten no bubbles are seen


Use the information in the table to put the four metals in order of their reactivity.

Put the least reactive metal first.

q3b_0620-s20-qp-32_cie-igcse-chemistry

5b2 marks

The table shows some observations about the reactivity of four metals with dilute hydrochloric acid.

metal reaction with hydrochloric acid
calcium a rapid stream of bubbles is seen
lead no bubbles are seen
manganese a slow stream of bubbles is seen
tin a few bubbles slowly form

Use the information in the table to put the four metals in order of their reactivity.

Put the least reactive metal first.

q3b_0620-s20-qp-32_cie-igcse-chemistry

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1a6 marks

Tin is an element in Group IV.

The position of tin in the reactivity series is:

 
zinc
iron
tin
copper
 
i)
For each of the following, decide if a reaction would occur. If there is a reaction, complete the equation, otherwise write ‘no reaction’.
 
Cu + Sn2+ → ..........................................
 
Fe + Sn2+ → ..........................................
 
Sn + Zn2+ → ..........................................
 
[4]
 
ii)
Name the three products formed when tin(II) nitrate is heated.
 
[2]
1b4 marks

Extended Only

Aqueous tin(II) sulfate is electrolysed using carbon electrodes. This electrolysis is similar to that of aqueous copper(II) sulfate using carbon electrodes.

i)
What is the product at the negative electrode (cathode)?

[1]

ii)
Write the equation for the reaction at the positive electrode (anode).


[2]

iii)
Name the acid formed in this electrolysis.

[1]
1c4 marks

Steel articles can be plated with tin or zinc to prevent rusting.

When the zinc layer is damaged exposing the underlying steel, it does not rust, but when the tin layer is broken the steel rusts. Explain.

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2a3 marks

This question is about alloys. 

Brass is an alloy which contains zinc.
 

i)
Name the other metal in brass.
 
[1]
 
ii)
Suggest two reasons why an alloy such as brass is preferred to either of its constituent metals.
 
[2]
2b5 marks

In an experiment to investigate the rate of rusting of steel, three pieces of steel were used.

One piece of steel was completely coated with copper, one piece completely coated with zinc and the third piece was left uncoated. All three pieces were left exposed to the atmosphere.

i)
Explain why the uncoated piece started to rust.
[1]

ii)
The coating on both of the other two pieces was scratched, exposing the steel.

The piece of steel coated with zinc still did not rust but the copper-coated piece of steel rusted very rapidly.

Explain these observations in terms of the formation of ions and the transfer of electrons.

[4]

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3a6 marks

Separate: Chemistry and Extended Only

One way of establishing a reactivity series is by displacement reactions.

A series of experiments was carried out using the metals lead, magnesium, zinc and silver.

Each metal was added in turn to aqueous solutions of the metal nitrates.

The order of reactivity was found to be:

 

magnesium

zinc

lead

silver

most reactive 

arrow

least reactive

 
i)
Complete the table.
 
Y = reacts
N = does not react
 
  metal
aqueous
solution

lead
Pb

magnesium
Mg
zinc
Zn
silver 
Ag
lead(II)
nitrate
  Y Y N
magnesium
nitrate
       
zinc 
nitrate
       
silver
nitrate
       
 
[3]
 
ii)
Displacement reactions are redox reactions.
 
On the following equation, draw a ring around the reducing agent and an arrow to show the change which is oxidation.
 
Zn + Pb2+ → Zn2+ + Pb
 
[2]
 
iii)
Complete the following ionic equation.
 
Zn + 2Ag+ → ....... + .......
 
[1] 
3b6 marks

Extended Only

Another way of determining the order of reactivity of metals is by measuring the voltage and polarity of simple cells. The polarity of a cell is shown by which metal is the positive electrode and which metal is the negative electrode. An example of a simple cell is shown below.

screen-shot-2022-09-05-at-19-51-28
i)
Mark on the above diagram the direction of the electron flow.
[1]

ii)
Explain, in terms of electron transfer, why the more reactive metal is always the negative electrode.
[2]

The following table gives the polarity of cells using the metals zinc, lead, copper and manganese.

Cell Electrode 1 Polarity Electrode 2 Polarity 
A Zinc Lead +
B Manganese Lead +
C Copper + Lead

iii)
What information about the order of reactivity of these four metals can be deduced from the table?
[2]
iv)
What additional information is needed to establish the order of reactivity of these four metals using cells? 
[1]

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4a5 marks

Extended Only

Excess hydrochloric acid was added to powdered zinc. The hydrogen evolved was collected and its volume measured every 20 seconds. The experiments were repeated at the same temperature using the same number of moles of powdered magnesium and aluminium.

screen-shot-2022-09-16-at-11-35-49

Identify metals A, B and C by choosing from zinc, magnesium and aluminium. Give a reason for each choice.


Metal A

Metal B

Metal C
4b3 marks

Extended Only

Using ‘moles’, explain why two of the metals form the same volume of hydrogen but the third metal forms a larger volume.

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5a6 marks

Extended Only

The reactions of a metal and the thermal stability of some of its compounds are determined by the position of the metal in the reactivity series.

To find the order of reactivity of the metals, cobalt, magnesium, silver and tin, the following experiments were carried out.

Experiment Result
Tin plus silver(I) nitrate solution Silvery layer on tin
Magnesium plus tin(II) nitrate solution Grey deposit on magnesium
Tin plus cobalt nitrate solution No reaction

i)
Give as far as possible the order of reactivity of these metals.
Write the least reactive first.
[2]

ii)
What additional experiment needs to be done to put all four metals in order of reactivity?
[1]

iii)
Write an ionic equation for the reaction between tin atoms and silver(I) ions. Indicate on the equation the change which is oxidation.

[3]

5b6 marks

Extended Only

A cell consists of two different metal electrodes in an electrolyte. Three possible cells are shown below.

screen-shot-2022-09-21-at-10-47-44
i)
Why is the more reactive metal the negative electrode?
[2]
ii)
How can you deduce that zinc is more reactive than tin?
[1]
iii)
How could you change the zinc / copper cell to have a voltage greater than 1.1V?
[1]
iv)
Complete the labelling of the zinc/tin cell.
[2]

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6a4 marks

Extended Only

In the following list of ionic equations, the metals are in order of reactivity.

screen-shot-2022-09-21-at-15-31-01

i)
In the space at the top of the series, write an ionic equation that includes a more reactive metal.
[1] 
ii)
Define oxidation in terms of electron transfer.
[1] 
iii)
Explain why the positive ions are likely to be oxidising agents.
[1] 
iv)
Which positive ion(s) can oxidise mercury metal (Hg)?
[1] 
6b3 marks

Extended Only

The following diagram shows a simple cell.

screen-shot-2022-09-21-at-15-52-55
i)
Predict how the voltage of the cell would change if the tin electrode was replaced with a silver one.
[1]
ii)
Which electrode would go into the solution as positive ions? Give a reason for your choice.
[1]
iii)
State how you can predict the direction of the electron flow in cells of this type.
[1]

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7a2 marks

Separate: Chemistry and Extended Only

Displacement reactions occur between metals and metal ions. Displacement reactions can be used to determine the order of reactivity of metals such as lead (Pb), nickel (Ni), and silver (Ag).

The ionic equation for a displacement reaction is shown.

Ni (s) + Pb2+ (aq) rightwards arrowPb (s) + Ni2+ (aq)

The ionic half-equations for this reaction are shown.

Ni (s) rightwards arrow Ni2+ (aq) + 2e

Pb2+ (aq) + 2erightwards arrow Pb (s)

The ionic half-equations show that electrons are donated by nickel atoms and accepted by lead ions.

Identify the reducing agent in the displacement reaction. Give a reason for your answer.

reducing agent _________________________________________

reason_________________________________________________

7b1 mark

Extended Only

What is the general term given to the type of reaction in which electrons are transferred from one species to another?

7c2 marks

Extended Only

The ionic equation for another displacement reaction is shown.


Pb (s) + 2Ag+ (aq) rightwards arrow 2Ag (s) + Pb2+ (aq)


Write the two ionic half-equations for this reaction.

7d1 mark

Use the information in (a) and (c) to put the three metals lead, nickel and silver in order of reactivity.q7c-0620_s19_qp_42

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1a3 marks

The position of aluminium in the reactivity series of metals is shown below.

magnesium
aluminium
zinc
copper

Aluminium is extracted by the electrolysis of its molten oxide.

1ep-wTSp_electrolysis-of-aluminium-oxide-3

i)
Name the main ore of aluminium.

[1]

ii)
Why does the molten electrolyte contain cryolite?

[1]

iii)
Oxygen is produced at the positive electrode (anode). Name another gas which is given off at this electrode.

[1]

1b3 marks

Aluminium reacts very slowly with aqueous copper(II) sulphate.


2Al(s) + 3CuSO4(aq)  → Al2(SO4)3(aq) + 3Cu(s)

i)
Which of the two metals has the greater tendency to form ions?
[1]

ii)
Describe what you would see when this reaction occurs.
[1]

iii)
Explain why aluminium reacts so slowly.
[1]

1c4 marks

Complete the following table by writing “reaction” or “no reaction” in the spaces provided.

oxide type of oxide reaction with acid reaction with alkali
magnesium basic    
aluminium amphoteric    

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2a3 marks

Give three differences in physical properties between the Group I metal, potassium, and the transition element, iron.

2b5 marks

The following metals are in order of reactivity.

potassium
zinc
copper

For those metals which react with water or steam, name the products of the reaction, otherwise write ‘no reaction’.

      Potassium: 
      Zinc:
      Copper:

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3a4 marks

Rusting of steel can be prevented by coating the steel with a layer of zinc.

Explain, in terms of electron transfer, why steel does not rust even if the layer of zinc is scratched so that the steel is exposed to air and water.

3b6 marks

When a sample of steel is added to dilute hydrochloric acid, an aqueous solution of iron(II) chloride, FeCl2, is formed.

When a sample of rust is added to dilute hydrochloric acid, an aqueous solution of iron(III) chloride, FeCl3, is formed.

i)
Aqueous sodium hydroxide is added to the solutions of iron(II) chloride and iron(III) chloride.

Complete the table below, showing the observations you would expect to make.

  Iron(II) chloride solution Iron(III) chloride solution
Aqueous
sodium hydroxide
   

[2]

Solutions of iron(II) chloride and iron(III) chloride were added to solutions of potassium iodide and acidified potassium manganate(VII). The results are shown in the table.

  Iron(II) chloride solution Iron(III) chloride solution
Potassium
iodide solution
No change Solution turns
from colourless
to brown
Acidified potassium
manganate(VII)
solution
Solution turns
from purple
to colourless
No change

ii)
What types of substance cause potassium iodide solution to turn from colourless to brown?

[1]

iii)
What types of substance cause acidified potassium manganate(VII) solution to turn from purple to colourless?
[1]
iv)
Which ion in iron(III) chloride solution causes potassium iodide solution to turn from colourless to brown?
[1]
v)
Which ion in iron(II) chloride solution causes acidified potassium manganate(VII) solution to turn from purple to colourless?
[1]

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47 marks

The reactivity series of metals given below contains both familiar and unfamiliar elements.
For most of the unfamiliar elements, which are marked *, their common oxidation states are given.

barium * Ba
lanthanum * La   (+3)
magnesium  
zinc  
chromium * Cr   (+2), (+3), (+6)
iron  
copper  
palladium * (+2)

Choose metal(s) from the above list to answer the following questions.

i)
Which two metals would not react with dilute hydrochloric acid?

[2]

ii)
Which two unfamiliar metals (*) would react with cold water?

[2]

iii)
What is the oxidation state of barium?

[1]

iv)
Name an unfamiliar metal (*) whose oxide cannot be reduced by carbon.

[1]

v)
Why should you be able to predict that metals such as iron and chromium have more than one oxidation state?

[1]

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5a9 marks

The reactivity series lists metals in order of reactivity.

To find out which is the more reactive metal, zinc or tin, the following experiment could be carried out.

cie-igcse-sq-9-2-practical-

This experiment could be carried out with other metals and the results are recorded in a table. Then the order of reactivity can be deduced.

i)
The order was found to be:
manganese  - most reactive
zinc
tin
silver - least reactive


Complete the table of results from which this order was determined.

cie-igcse-sq-9-2-chart-results-

[3]

ii)
Write the ionic equation for the reaction between tin atoms and silver(I) ions.

[2]

iii)
The following is a redox reaction.

Mn + Sn2+ rightwards arrowMn2+ + Sn

Indicate on the equation the change which is oxidation. Give a reason for your choice.

[2]

iv)
Explain why experiments of this type cannot be used to find the position of aluminium in the reactivity series.

[2]

5b2 marks

Potassium and calcium are very reactive metals at the top of the series. Because their ions have different charges, K+ and Ca2+, their compounds behave differently when heated.

 

Explain why the ions have different charges.

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6a4 marks

Steel is an alloy made from impure iron.

Both iron and steel rust. The formula for rust is Fe2O3.2H2O. It is hydrated iron(III) oxide.

i)
Name the two substances that must be present for rusting to occur.
[2]
ii)
Painting and coating with grease are two methods of preventing iron or steel from rusting. Give two other methods.
[2]
6b3 marks
i)
Name a reagent that can reduce iron(III) oxide to iron.

[1]

ii)
Write a symbol equation for the reduction of iron(III) oxide, Fe2O3, to iron.

[2]

6c
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3 marks
i)
Calculate the mass of one mole of Fe2O3.2H2O.
[1]

ii)
Use your answer to (i) to calculate the percentage of iron in rust.
[2]
6d3 marks

Iron from the blast furnace is impure. Two of the impurities are carbon and silicon. These are removed by blowing oxygen through the molten iron and adding calcium oxide.

 

i)
Explain how the addition of oxygen removes carbon.
[1]
ii)
Explain how the addition of oxygen and calcium oxide removes silicon.
[2]

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7a2 marks

Some reactions of metals W, X, Y and Z are given below.

metal reaction with water  reaction with hydrochloric acid
W A few bubbles form slowly in cold water. Vigorous reaction. Gas given off.
X Vigorous reaction. Metal melts. Gas given off. Explosive reaction. Should not be attempted.
Y No reaction. No reaction.
Z Does not react with cold water. Hot metal reacts with steam. Steady fizzing.

Arrange these metals in order of reactivity.

Most reactive  ............................................
  ............................................
  ............................................
Least reactive  ............................................

7b2 marks

Which of these metals could be?


Magnesium ................
[1] 
Copper ................
[1] 
7c6 marks

The equation for the reaction of X with cold water is given below.

2X (s) + 2H2O (l) → XOH (aq) + H2 (g)

i)
Describe the test you would use to show that the gas evolved is hydrogen.

[1]

ii)
How could you show that the water contained a compound of the type XOH?

[2]

iii)
In which group of the Periodic Table does metal X belong?

[1]

iv)
The ore of X is its chloride. Suggest how metal X could be extracted from its chloride.

[2]

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