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Essential Chemistry for IGCSE - Air And Water (Section 6)

1
What is a practical method to prevent rusting?
Answer
(C)
Coating iron with paint
2
Which of the following compounds does NOT contribute to acid rain?
Answer
(D)
Water vapor (H2O)
3
What is the percentage of the Earth's atmosphere composed of oxygen?
Answer
(A)
21%
4
Which of the following is a greenhouse gas?
Answer
(C)
Methane
5
Which of the following is a major contributor to the enhanced greenhouse effect?
Answer
(B)
Increased levels of carbon dioxide
6
Which gas is removed from the atmosphere during photosynthesis?
Answer
(B)
Carbon Dioxide
7
What does the word 'corrosion' refer to?
Answer
(C)
The attack on a metal by chemicals.
8
Which gas is not a major component of air?
Answer
(D)
Helium
9
What are the main products formed during the burning of a fuel like octane (C8H18)?
Answer
(B)
Carbon dioxide and water
10
What is the main concern regarding the increase of greenhouse gases in the atmosphere?
Answer
(C)
Global warming
11
What is the primary function of a modern water treatment plant?
Answer
(B)
To remove harmful substances and bacteria from water.
12
Why is zinc considered a sacrificial metal in the context of rust prevention?
Answer
(B)
Because it corrodes in preference to the iron.
13
What is a key step in the water purification process?
Answer
(C)
Removing harmful substances.
14
What is one thing that increases the concentration of greenhouse gasses?
Answer
(B)
Burning of fossil fuels
15
What could cause the 'carbon cycle' to be unbalanced?
Answer
(A)
Increased deforestation.
16
What is the impact of burning fossil fuels on the carbon cycle?
Answer
(C)
It puts the carbon cycle out of balance.
17
What is the primary role of a catalytic converter?
Answer
(B)
To reduce the amount of pollutants released from vehicles.
18
What do modern water treatment plants aim to eliminate?
Answer
A
B
C
19
What is the name of the bacteria that can convert the nitrogen gas?
Answer
(B)
Denitrifying bacteria
20
What type of reaction results in the conversion of sulfur dioxide into sulfuric acid?
Answer
(C)
Oxidation
21
What are the main elements of the air?
Answer
A
C
D
22
What is the effect of the 'burning of fossil fuels' on the atmosphere?
Answer
(B)
Increase in atmospheric CO2
23
What type of radiation does the Earth's surface absorb?
Answer
(B)
Infrared radiation
24
Which of these statements about the carbon cycle is correct?
Answer
(D)
The amount of carbon dioxide put into the atmosphere by respiration is roughly the same as carbon dioxide removed by photosynthesis.
25
What are some of the causes for the global warming?
Answer
A
B
C
26
What is the source of acid rain?
Answer
(B)
Burning of fossil fuels and volcanoes
27
What is used to separate the gases in the air?
Answer
(C)
Fractional distillation
28
What is the primary source of methane emissions mentioned in the text?
Answer
(C)
Decomposition of organic matter and animal waste
29
What is a key aspect of water treatment?
Answer
(C)
Removal of bacteria
30
Which of the following processes *removes* carbon dioxide from the atmosphere?
Answer
(C)
Photosynthesis
31
What is a major component of greenhouse gases in the atmosphere, as mentioned in the text?
Answer
(C)
Carbon dioxide
32
What is the primary cause for acid rain?
Answer
(C)
A combination of both.
33
Why is the amount of carbon dioxide in the air usually constant?
Answer
(B)
Because the release of carbon dioxide is balanced by the uptake.
34
What is the general formula for hydrated iron(III) oxide(rust)?
Answer
(B)
Fe2O3.H2O
35
What is an effect of the greenhouse effect, as stated in the text?
Answer
(A)
Warming the Earth
36
What is a common type of pollutant found in the air, as discussed in the text?
Answer
(C)
Carbon monoxide
37
What is the main use of the information on the water presented in 15.1?
Answer
(D)
All of the above.
38
How does a catalytic converter reduce air pollution?
Answer
(B)
By converting nitrogen oxides and unburnt hydrocarbons into harmless gases.
39
What does the equation C6H12O6 + 6O2 -> 6CO2 + 6H2O represent?
Answer
(B)
Respiration
40
What are some potential effects of global warming, as mentioned in the text?
Answer
A
B
D
41
What process converts nitrogen gas to a usable form?
Answer
(B)
Nitrification
42
Which of the following statements is true about the impact of the greenhouse effect on the Earth?
Answer
(C)
The greenhouse effect keeps the Earth warmer than it would otherwise be.
43
In the context of air pollution, what are 'particulates'?
Answer
(B)
Small solid or liquid particles in the air
44
What is the main cause of the greenhouse effect?
Answer
(B)
Increased concentration of greenhouse gases.
45
What is the primary source of carbon monoxide?
Answer
(B)
Incomplete combustion of fuels.
46
What is the role of chlorophyll in photosynthesis?
Answer
(B)
It traps light and acts as a catalyst.
47
What is a consequence of global warming?
Answer
(C)
Melting of polar ice caps
48
What is a result of rising levels of carbon dioxide in the atmosphere?
Answer
(C)
Global warming
49
What are the necessary conditions for rusting to occur?
Answer
(D)
Both air and water
50
What is the name of the process in which glucose is broken down to release energy?
Answer
(B)
Respiration