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Carbon Dioxide
STRUCTURE |
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COMMERCIAL
PREPARATION |
Produced as a by-product of fermentation
C6H12O6 (aq) -> 2C2H5OH (aq) + 2CO2 (g)
And by the heating of limestone
CaCO3 (s) -> CaO (s) + CO2 (g) |
LABORATORY
PREPARATION |
By the reaction of the dilute hydrochloric acid with calcium carbonate (as marble chips)
CaCO3 (s) + HCI (aq) -> CaCl2 (aq) + CO2 (g) + H2O (l) |
| PROPERTIES |
Colourless, odourless, denser than air, will not support combustion, converts from the solid state to the gaseous state directly (sublimes), slightly soluble, solutions slightly acidic, solubility increases with an increase in pressure, absorbs heat (it is a greenhouse gas that contributes to the greenhouse effect) |
| TESTING |
Limewater (calcium hydroxide) turns cloudy when carbon dioxide is bubbled through it due to the formation of the white precipitate calcium carbonate.
CO2 (g) + Ca(OH)2 (s) -> CaCO3 (s) + H2O (l) |
| USES |
Used to make carbonated drinks, solid CO2 (dry ice) is used as a refrigerant, used in fire extinguishers and used for preserving fruit. |
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