IGCSEChemistry: Double ScienceEdexcelExam Questions2. Inorganic ChemistryGases in the Atmosphere

Gases in the Atmosphere (Edexcel IGCSE Chemistry: Double Science)

Exam Questions

1 hour13 questions
Easy
Medium
1a4 marks

This question is about gases in the atmosphere.

a)
The box gives the names of some gases in the atmosphere.

argon carbon dioxide helium nitrogen oxygen



Choose gases from the box to answer these questions.

Each gas may be used once, more than once or not at all.

i)
Identify a noble gas.

(1)

ii)
Identify a gas that makes up about 78% of the atmosphere.

(1)

iii)
Identify a greenhouse gas.

(1)

iv)
Identify a gas produced by the thermal decomposition of calcium carbonate.

(1)

How did you do?

1b2 marks
b)
Sulfur reacts with oxygen to produce sulfur dioxide gas.

i)
Write a chemical equation for this reaction.

[1]

ii)
State an environmental problem caused when sulfur dioxide gas dissolves in water in the atmosphere.

[1]

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2a3 marks

A teacher uses this apparatus to find the percentage of oxygen in a gaseous mixture of oxygen and argon.

oxygen-composition-of-air-experiment

This is the teacher’s method.

  1. Heat the copper powder
  2. Push the plunger on syringe A to pass the mixture of oxygen and argon over the hot copper so that the mixture moves into syringe B
  3. Push the plunger on syringe B to pass the mixture of oxygen and argon over the hot copper so that the mixture moves into syringe A
  4. Record the reading on syringe A
  5. Repeat Steps 2, 3 and 4 a number of times

The volume of gas decreases as the oxygen reacts with the copper.

Argon is unreactive so does not react with the copper.

 The copper powder turns black. 

a) i)
Give a reason why the copper powder is heated.
 
(1)
 
ii)
State why argon is unreactive.
 
(1)
 
iii)
Give the name of the black powder that forms when the oxygen reacts with the copper. 
 
(1)

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2b
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b)
The table shows the teacher’s results.
 
Reading number Reading on syringe A in cm3 
Start 78
1 70
2 67
3 65
4 63
5 61
6 60
7 59
8 58
9 58
10 58
 
i)
State how the results show that all the oxygen has reacted.
 
(1)
 
ii)
The volume of gas in the glass tube and connecting tubes is 175 cm3.
 
Use this value and the results table to calculate the percentage of oxygen in the mixture of oxygen and argon.
 
(3)
 
iii)
Suggest one reason why the calculated percentage of oxygen in the mixture may not be accurate.
 
(1)

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3a4 marks

This question is about gases.

a)
The box gives the names of some gases.

  argon carbon dioxide hydrogen nitrogen oxygen

Use gases from the box to answer these questions.

Each gas may be used once, more than once or not at all.

i)
Name the most abundant gas in the Earth’s atmosphere.

(1)

ii)
Name the gas that is a compound.

(1)

iii)
Name the least reactive of the gases.

(1)

iv)
Name the gas formed by the complete combustion of hydrocarbons.

(1)

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3b1 mark
b)
Describe the test for hydrogen gas.

(1)

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4a2 marks

This question is about gases in the air.

The pie chart represents the percentages of gases in dry, unpolluted air.

Gases with percentages of less than 1% in air are called trace gases.

air-comopsition

a) i)
Which of these is gas Z?
 
(1)
 
  ☐ A hydrogen 
  ☐ B methane
  ☐ C neon
  ☐ D nitrogen

ii)
Which of these is the approximate percentage of oxygen in dry, unpolluted air?
 
(1)
 
  ☐ A 0.04%
  ☐ B 0.9%
  ☐ C 21%
  ☐ D 35%

How did you do?

4b4 marks
b)
One of the trace gases is carbon dioxide.
 
i)
Identify two reactions that produce carbon dioxide by placing a tick (✔) in two boxes.
 
cracking an alkane  
complete combustion of an alkane  
reaction between magnesium and hydrochloric acid  
rusting of iron  
thermal decomposition of copper(II) carbonate  
 
(2)
 
ii)
Name an environmental problem that is caused by the percentage of carbon dioxide increasing in the atmosphere.
 
(1)
 
iii)
Name the trace gas with the highest percentage in dry, unpolluted air.
 
(1)

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4c2 marks
c)
Rainwater is acidic because carbon dioxide dissolves in water to form carbonic acid.
 
Acid rain is more acidic than rainwater because acidic pollutant gases also dissolve in water.
 
i)
Give the name of the acid that forms when nitrogen dioxide dissolves in water.
 
(1)
 
ii)
Name another pollutant gas that also forms acid rain.
 
(1)

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5a4 marks

This question is about gases in the atmosphere.

a)
The box gives the names of some gases in the atmosphere.

     argon                     carbon dioxide                helium

                   nitrogen                                oxygen

Use gases from the box to answer the questions.

Each gas may be used once, more than once or not at all.

i)
Identify the two noble gases.

(1)

ii)
Identify the gas that is a compound.

(1)

iii)
Identify the most abundant gas in the atmosphere.

(1)

iv)
Identify the greenhouse gas.

(1)

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5b1 mark
b)
Describe the test for oxygen.

(1)

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11 mark

Air is a mixture of gases.

What is the approximate percentage of nitrogen in air?

(1)

  ☐ A 1
  ☐ B 20
  ☐ C 25
  ☐ D 78

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2a2 marks

The percentage by volume of oxygen in air can be found by using the rusting of iron. A student sets up this apparatus to measure the volume of oxygen in a sample of air.

screen-shot-2022-10-10-at-12-55-10

An excess of wet iron filings is used. At the start of each experiment, the reading on the syringe is recorded and the apparatus is then left for a week so that the reaction is complete. The reading on the syringe is then recorded again.

a)
The diagram shows the readings in one experiment.

screen-shot-2022-10-10-at-12-55-16

   Complete the table to show:

  • the syringe reading at the end of this experiment
  • the volume of oxygen used in the experiment.
syringe reading at start / cm3 76
syringe reading at end / cm3  
volume of oxygen used / cm3  

(2) 

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2b3 marks
b)
The table shows the results recorded by a different student in her experiment.

volume of air in conical flask / cm3 100
volume of air in connecting tube / cm3 10
original volume of air in syringe / cm3 80
final volume of air in syringe / cm3 43

Calculate the percentage of oxygen in air using these results.



percentage of oxygen = ............. %

(3) 

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2c3 marks
c)
The table shows some possible causes of anomalous results in this experiment. Use terms from the box to complete the table, showing possible causes and their effects on the volume of oxygen used in this experiment.

decreased increased no effect 

   Each term may be used once, more than once, or not at all.

(3) 

Possible cause Effect on volume of oxygen used
wet iron filings not in excess  
apparatus left for 1 hour instead of 1 week  
apparatus left in a warmer place for 1 week  

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31 mark

The approximate percentage of oxygen in air can be determined in the laboratory using this apparatus.

2-3-q2-edexcel-igcse-chemistry

The steps for the method are shown below.

The steps shown are not in the correct order.

Step K:  Place some damp iron wool and a rubber bung in the top of the tube
Step L:  Leave the apparatus for a few days
Step M:  Place a graduated glass tube in a beaker of water
Step N:  Record the reading of the water level in the tube
Step O:  Record the reading of the water level again

  

Which of the following shows the correct order of the steps above?

(1)

  ☐ A M, K, N, L, O
  ☐ B K, M, N, L, O
  ☐ C M, N, K, L, O
  ☐ D K, M, N, L, O

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4a1 mark

A teacher uses the reaction between phosphorus and oxygen to calculate the percentage of oxygen in air.
She uses this apparatus and excess phosphorus.

phosphorus-experiment

The volume of gas in the tube decreases as the phosphorus reacts with oxygen.
The teacher measures the volume of gas in the tube at one-minute intervals.
The table shows the teacher’s results.

Time in minutes Volume of gas in tube in cm3
0 48.5
1 41.0
2 38.0
4 37.5
5 37.0
6 37.0
7 37.0



a)
State how the results show that all the oxygen has reacted.

(1)

How did you do?

4b1 mark
b)
Give one change to this experiment that would make the results more accurate.

(1)

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4c
Sme Calculator3 marks
c)
Use the results to calculate the percentage of oxygen in air.
Give your answer to one decimal place.

(3)

 

percentage = ...........................%

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51 mark

Carbon dioxide is a gas present in air.

Which statement is not correct about carbon dioxide?

(1)

  ☐ A When bubbled through limewater, carbon dioxide turns limewater cloudy
  ☐ B It is produced when copper(II) carbonate undergoes thermal decomposition
  ☐ C It is the third most abundant gas in the atmosphere
  ☐ D It is a greenhouse gas that contributes to climate change

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6a1 mark

A student uses this apparatus to investigate the effect of heat on different solid metal carbonates.

1cr-q5

This is the student’s method:

  • Use a spatula to put some metal carbonate in the boiling tube
  • Fit the delivery tube into position
  • Pour some limewater into the test tube
  • Start a timer and immediately begin to heat the metal carbonate
  • Record the time when a change first occurs in the limewater

The student repeats the method using different metal carbonates.

When a metal carbonate is heated a reaction sometimes occurs.
The equation for the reaction is:

metal carbonate → metal oxide + carbon dioxide

a)
State the name given to this type of reaction.
(1)

How did you do?

6b2 marks
b)
State two variables that the student should control in this investigation.

1. ...........................................

2. ...........................................

(2)

How did you do?

6c1 mark
c)
Suggest why bubbles appear in the limewater immediately after heating has started but before there is any change to the metal carbonate.
(1)

How did you do?

6d2 marks
d)
Explain the purpose of limewater in this investigation.
(2)

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6e3 marks
e)
The table shows some of the results for the student’s investigation.
 
Metal carbonate Colour change of solid  Time taken for any
change in limewater
calcium carbonate remains white  90 seconds
sodium carbonate remains white  no change
copper(II) carbonate    50 seconds

i)
State the colour change that occurs for copper(II) carbonate.

from ...................................... to ...................................

(2)

ii)
Give a chemical equation for this reaction of copper(II) carbonate.
(1)

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6f3 marks
f)
There is a relationship between the position of a metal in the reactivity series and how easily the metal carbonate reacts when heated.

I)
Use the student’s results and your own knowledge to deduce this relationship.
(2)

ii)
State how you should extend the investigation to see if your deduction is correct.
(1)

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71 mark

Metal carbonates undergo thermal decomposition when heated.

Which is a correct balanced symbol equation for the thermal decomposition of a metal carbonate?

(1)

  ☐ A LiCO3 → LiO + CO2
  ☐ B Mg2CO3 → Mg2O + CO2
  ☐ C CaCO3 + CO2 → CaO 
  ☐ D CuCO3 → CuO + CO2

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81 mark

Combustion reactions involve a chemical change in which oxygen reacts with elements or compounds to produce oxides.

Which is the correct statement about combustion?

(1)

  ☐ A Combustion reactions are also reduction reactions
  ☐ B During the combustion of sulfur, a blue flame is observed and a colourless, poisonous gas is produced
  ☐ C All combustion reactions are endothermic
  ☐ D

The balanced symbol equation for the combustion of hydrogen is: H2 + O2 → H2O2

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