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Experiment 7.1A: Tests for oxygen and carbon dioxide
Objective: To identify oxygen and
carbon dioxide
Results:
|
Observation
|
Test results
|
|
|
Oxygen
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Carbon dioxide
|
|
|
1: colour of gas
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Colourless
|
Colourless
|
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2: smell of gas
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Odourless
|
Odourless
|
|
3: change of
burning splint
|
Burns more brightly
|
Goes out
|
|
4: change of
glowing splint
|
Relights
|
Goes out
|
|
5: colour change of hydrogencarbonate indicator
|
No observable change
|
From red to yellow
|
|
|
|
|
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6: colour change
of lime water
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No observable change
|
From colourless to milky
|
|
|
|
|
Discussion:
Ø
Oxygen can relight a glowing splints.
Ø
Carbon dioxide can turn lime water from colourless
to milky.
Ø
Carbon dioxide can turn hydrogencarbonate indicator from red to
yellow.
Experiment
7.1B: Tests for water and water vapour
Objective: To carry out a simple test
for water and water vapour.
Results:
|
Observation
|
Colour / Colour Change
|
|
|
Dry
|
Wet
|
|
|
Cobalt
chloride paper
|
Blue
|
Pink
|
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Cobalt chloride paper in air
|
The
colour changes from blue to pink
|
|
|
|
||
Discussion:
Ø
Cobalt chloride paper can be used to test for water.
Ø
From the result of dry cobalt chloride held in air
for one to two minutes, we can conclude that air
contains water vapour.
