UNIT 8937: SAMPLE ACTIVITY 10
SAMPLE ASSESSMENT ACTIVITIES AND SCHEDULES 6.47
8937 CHEMISTRY
LEVEL 1
FUELS
This activity assesses:
Unit:
Element:
8937
1
2
CONDITIONS:
Describe the nature and use of organic fuels (Level 1).
Categorise simple hydrocarbons and alcohols.
Describe the combustion of organic fuels.
Formal activity. Task C can be group practical work.
INSTRUCTIONS:
Task A
1.
Name the following straight chain hydrocarbons.
a)
b)
C2H6
H H H H
H C C C C H
H H H H
2.
c)
C8H18
d)
C3H6
e)
C2H5OH
Draw the structural formulae for the following straight chain hydrocarbons.
a)
hexane
b)
methane
c)
ethene
d)
C5H12
e)
methanol
1.1‰
ASSESSMENT ACTIVITY: FUELS
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6.48 SAMPLE ASSESSMENT ACTIVITIES AND SCHEDULES
UNIT 8937: SAMPLE ACTIVITY 10
Task B
The graph shows the boiling points of some alkanes plotted against the number of carbon
atoms in the straight chain molecule.
1.
As the number of carbon atoms increases, what happens to the boiling point of the
molecules?
2.
Use the graph to answer the following:
a)
Is C5H12 (pentane) likely to be a solid, liquid or gas at 20ºC?
b)
How many alkanes shown on the graph are gases at room temperature (25ºC)?
c)
How many alkanes shown on the graph are still liquids at 60ºC?
1.2‰
ASSESSMENT ACTIVITY: FUELS
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UNIT 8937: SAMPLE ACTIVITY 10
SAMPLE ASSESSMENT ACTIVITIES AND SCHEDULES 6.49
Task C
The following apparatus was used to identify the products of complete combustion of petrol.
Useful information
Blue-cobalt chloride paper
• turns blue if water is produced
• stays pink in the absence of water
• no change in appearance if carbon monoxide is
produced
Limewater
• turns cloudy if carbon dioxide is produced
• stays clear if carbon monoxide is produced
• gets black spots in it if carbon is produced.
The gas burner was lit, the suction pump turned on, and the products of complete
combustion passed through the test tubes for 5 minutes.
1.
Describe what you would observe in each test tube.
2.
Name the TWO products of complete combustion of this fuel.
2.1‰
ASSESSMENT ACTIVITY: FUELS
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6.50 SAMPLE ASSESSMENT ACTIVITIES AND SCHEDULES
UNIT 8937: SAMPLE ACTIVITY 10
Task D
1.
Two identical beakers containing the same volume of water were placed on tripods at
the same height over bunsen flames of the same size.
The flame of one bunsen burner was yellow, while that of the other was blue.
Which beaker boiled first?
2.
An oxyacetylene torch can be adjusted to burn with a yellow sooty flame, or a clean
blue flame. Which flame is the hottest?
3.
If a car engine is turned incorrectly, not enough air mixes with the petrol during
combustion.
a)
What effect would this have on the energy produced by the engine?
b)
What health risks arise from this incomplete combustion?
2.2‰
ASSESSMENT ACTIVITY: FUELS
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ASSESSMENT GUIDE: CHEMISTRY - JUNE 1997
UNIT 8937: SAMPLE ACTIVITY 10
SAMPLE ASSESSMENT ACTIVITIES AND SCHEDULES 6.51
Assessment Schedule: Fuels
Unit Standard 8937
Task
Number
Element and
Performance
Criteria
A
1.1
Evidence
(The answers or performance expected from the
students)
1.
a) ethane
b) butane
c) octane
d) propene
Judgement
(A statement that defines the
standard to be achieved)
Four correct.
e) ethanol
2.
a)
H H H H H H
Four correct.
H C C C C C C H
H H H H H H
b)
H
H C H
H
c)
H
H
C C
H
d)
H
H H H H H
H C C C C C H
H H H H H
e)
H
H C OH
H
B
1.2
1.
Boiling point increases.
Correct answer.
2.
a) liquid
Two correct.
b) 4
c) 3
ASSESSMENT SCHEDULE: FUELS
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ASSESSMENT GUIDE: CHEMISTRY - JUNE 1997
6.52 SAMPLE ASSESSMENT ACTIVITIES AND SCHEDULES
Task
Number
Element and
Performance
Criteria
C
2.1
D
2.2
UNIT 8937: SAMPLE ACTIVITY 10
Evidence
(The answers or performance expected from the
students)
1.
Judgement
(A statement that defines the
standard to be achieved)
Tube I: Cobalt chloride paper turns pink
or colourless liquid forms.
Either answer given.
Tube II: Limewater turns milky/cloudy.
Correct answer.
2.
Carbon dioxide and water or CO2 and
H2O.
Both correctly named.
Formulae are acceptable.
1.
The beaker over the blue flame.
2.
The blue flame.
Two out of 1, 2 and 3 (a)
correct.
3.
(a) Engine would produce less energy.
A correct answer for 3 (b).
(b) Carbon monoxide or poisonous gas
is produced or some description of
the effect of carbon monoxide on the
body or effect of soot production on
lungs.
ASSESSMENT SCHEDULE: FUELS
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