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Experiment 7.1A: Tests for oxygen and carbon dioxide
Objective: To identify oxygen and
carbon dioxide
Results:
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Observation
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Test results
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Oxygen
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Carbon dioxide
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1: colour of gas
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Colourless
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Colourless
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2: smell of gas
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Odourless
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Odourless
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3: change of
burning splint
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Burns more brightly
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Goes out
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4: change of
glowing splint
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Relights
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Goes out
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5: colour change of hydrogencarbonate indicator
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No observable change
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From red to yellow
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6: colour change
of lime water
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No observable change
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From colourless to milky
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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:
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Observation
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Colour / Colour Change
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|
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Dry
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Wet
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Cobalt
chloride paper
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Blue
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Pink
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Cobalt chloride paper in air
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The
colour changes from blue to pink
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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.
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