(Ca(HCO 3 ) 2 ):
CaCO 3 (s) + H 2 O(ℓ) + CO 2 (g) → Ca2+(HCO 3 −)^2 (aq)This reaction can easily be reversed with increased temperature or decreased
pressure. This is the way stalagmites and stalactites form on the floors and roofs
of caves, respectively. The ground water containing calcium bicarbonate is
deposited on the roof and floor of the cave and decomposes into solid calcium
carbonate formations.
IMPORTANT USES OF CO 2
- Because CO 2 is the acid anhydride of carbonic acid, it forms the acid
when reacted with soft drinks, thus making them “carbonated” beverages.
CO 2 (g) + H 2 O(ℓ) → H 2 CO 3 (aq)- Solid carbon dioxide (−78°C), or “dry ice,” is used as a refrigerant
because it has the advantage of not melting into a liquid; instead, it sublimes
and in the process absorbs 3 times as much heat per gram as ice. - Fire extinguishers make use of CO 2 because of its properties of being 1
times heavier than air and not supporting ordinary combustion. It is used in
the form of CO 2 extinguishers, which release CO 2 from a steel cylinder in
the form of a gas to smother the fire. - Plants consume CO 2 in the photosynthesis process, in which chlorophyll
(the catalyst) and sunlight (the energy source) must be present. The reactants
and products of this reaction are:
TIP
Know the photosynthesis process.ORGANIC CHEMISTRY
Organic chemistry may be defined simply as the chemistry of the compounds of
carbon. Since Friedrich Wöhler synthesized urea in 1828, chemists have
synthesized thousands of carbon compounds in areas of dyes, plastic, textile
fibers, medicines, and drugs. The number of organic compounds has been