| Date | May 2017 | Marks available | 2 | Reference code | 17M.3.sl.TZ1.17 |
| Level | SL | Paper | 3 | Time zone | TZ1 |
| Command term | Predict | Question number | 17 | Adapted from | N/A |
Question
A link between the combustion of fossil fuels and an increase in the temperature of the Earth’s atmosphere was proposed over a century ago.
Suggest why it is only in recent years that specific predictions of the future effects of fossil fuel combustion have been made.
Carbon dioxide has two different bond stretching modes illustrated below.
Predict, with an explanation, whether these stretching modes will absorb infrared radiation.
Outline, giving the appropriate equation(s), how increasing levels of carbon dioxide will affect the pH of the oceans.
Many combustion processes also release particulate matter into the atmosphere. Suggest, giving your reason, how this might affect the temperature of the Earth’s surface.
Markscheme
computers can now carry out more complex calculations
OR
better understanding of the interactions between the various systems involved
OR
clear evidence of global warming
OR
«reliable» global temperature data now available
OR
techniques have been available to monitor carbon dioxide levels
Accept “better/faster computers”.
Accept “better modelling”.
Accept “better/more reliable/consistent data”.
Accept “better measuring techniques”.
Accept other scientifically based (not politically based) reasons.
Accept if specific relevant data is given.
Do not accept “increased combustion of fossil fuels” or “increased concerns about global warming”.
[1 mark]
symmetric stretching will not absorb IR
OR
asymmetric stretching will absorb IR
change in polarity/dipole «moment» required «to absorb IR»
[2 marks]
CO2(aq) + H2O(l) H+(aq) + HCO3–(aq) «and pH decreases»
OR
CO2(aq) + H2O(l) H2CO3(aq) AND H2CO3(aq) H+(aq) + HCO3–(aq) «and pH decreases»
Accept reversible or non-reversible arrows for all.
[1 mark]
reduce it AND absorbing/reflecting sunlight
Accept “reduce it because of global dimming”.
Accept “reduce it AND blocking sunlight”.
[1 mark]
Examiners report
Syllabus sections
- 17N.3.sl.TZ0.13d: Outline how water and carbon dioxide absorb infrared radiation.
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18M.3.sl.TZ1.9a:
Identify one naturally occurring greenhouse gas, other than carbon dioxide or water vapour, and its natural source.
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19M.3.hl.TZ1.15d(ii):
Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.
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17M.3.sl.TZ1.17d:
Many combustion processes also release particulate matter into the atmosphere. Suggest, giving your reason, how this might affect the temperature of the Earth’s surface.
-
18M.3.sl.TZ1.9c:
The concentrations of oxygen and nitrogen in the atmosphere are much greater than those of greenhouse gases. Outline why these gases do not absorb infrared radiation.
- 18N.3.hl.TZ0.14c: Contrast the importance of carbon dioxide and methane as greenhouse gases.
- 18N.3.sl.TZ0.11d: Contrast the importance of carbon dioxide and methane as greenhouse gases.
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17M.3.sl.TZ1.17c:
Outline, giving the appropriate equation(s), how increasing levels of carbon dioxide will affect the pH of the oceans.
-
17M.3.sl.TZ2.14a:
Identify which region, A or B, corresponds to each type of radiation by completing the table.
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19M.3.sl.TZ2.13a:
State one greenhouse gas, other than carbon dioxide.
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17M.3.sl.TZ1.17a:
Suggest why it is only in recent years that specific predictions of the future effects of fossil fuel combustion have been made.
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19M.3.sl.TZ1.11d(ii):
Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.
-
16N.3.sl.TZ0.13b:
(i) Describe the changes that occur at the molecular level when atmospheric carbon dioxide gas absorbs infrared radiation emitted from the Earth’s surface.
(ii) Other than changes to the acidity of oceans, suggest why the production of carbon dioxide is of greater concern than the production of water vapour.
-
20N.3.hl.TZ0.11e(ii):
Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.
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18M.3.sl.TZ2.11a:
Explain the molecular mechanism by which carbon dioxide acts as a greenhouse gas.
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19M.3.sl.TZ1.11d(i):
Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.
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18M.3.sl.TZ2.11b:
Discuss the significance of two greenhouse gases, other than carbon dioxide, in causing global warming or climate change.
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19M.3.hl.TZ1.15d(i):
Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.
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17N.3.sl.TZ0.13c:
Climate change or global warming is a consequence of increased levels of carbon dioxide in the atmosphere. Explain how the greenhouse effect warms the surface of the earth.
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18N.3.sl.TZ0.11e:
Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.
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16N.3.sl.TZ0.13a:
Explain the effect of the increasing concentration of atmospheric carbon dioxide on the acidity of oceans.
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18N.3.hl.TZ0.14d:
Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.
-
19M.3.hl.TZ2.18a:
Describe the effect of infrared (IR) radiation on carbon dioxide molecules.
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19M.3.hl.TZ2.18b:
Outline one approach to controlling industrial emissions of carbon dioxide.
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17M.3.sl.TZ2.14b.ii:
Describe how large amounts of CO2 could reduce the pH of the ocean using an equation to support your answer.
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19M.3.sl.TZ2.13c:
Outline one approach to controlling industrial emissions of carbon dioxide.
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20N.3.hl.TZ0.11e(i):
When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.
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19M.3.sl.TZ2.13b:
Describe the effect of infrared (IR) radiation on carbon dioxide molecules.
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20N.3.sl.TZ0.9f(i):
When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.
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18M.3.sl.TZ1.9b:
Formulate an equation that shows how aqueous carbon dioxide produces hydrogen ions, H+(aq).
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17M.3.sl.TZ2.14b.i:
Oceans can act as a carbon sink, removing some CO2(g) from the atmosphere.
CO2(g) CO2(aq)
Aqueous carbon dioxide, CO2(aq), quickly reacts with ocean water in a new equilibrium reaction. Construct the equilibrium equation for this reaction including state symbols.
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20N.3.sl.TZ0.9f(ii):
Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.
