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The combustion of carbon
Description of the combustion of carbon
Carbon is a
substance existing under various forms but the one that may most easily
burn is the charcoal (also used in drawing).
- Step 1:
The initiation allows the combustion to start.
The charcoal is placed in a flame until it becomes hot enough to emit a
red light: the charcoal is then incandescent.
- Step 2: Combustion of charcoal in the air
The charcoal is removed from the flame.
Charcoal still burns in the air and remains incandescent.
- Step 3: Combustion of charcoal in the pure dioxygen.
The incandescent charcoal is placed in a container initially containing
When the incandescent fusain is placed in the container, a flame forms
and some sparks are projected.
Combustion is more intense in pure dioxygen than in air.
- Step 4:
End of combustion
After a few moment the combustion becomes less and less intense
and then stops.
A part of the fusain has disappeared during combustion.
- Step 5:
Analysis of the content of the container where furcoal has burnt.
The limewater test is positive and indicates the presence of carbon
Interpretation of the combustion of carbon
is stronger in pure dioxygen (100% dioxygen) than in air (21%
dioxygen):dioxygen is required for combustion of charcoal.
- In pure dioxygen combustion stops even if charcoal hasn't
totally disappeared. It means that another compound lacks: dioxygen.
Combustion of charcoal consumes dioxygen.
- A part of
charcoal (composed of carbon) has disappeared during combustion:
This combustion consumes carbon
-Limewater test indicates the presence of carbon dioxide( limewater
turns cloudy): Carbon dioxide has formed during this combustion
The combustion of charcoal in dioxygen is a chemical transformation
during which some compounds disappear (carbon and dioxygen) and another
compound appears (carbon dioxide).
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