You’ve heard,
carbon dioxide is a polluting agent.
carbon dioxide causes global warming.
carbon dioxide is the gas that we breathe out.
but did you know that increase concentrations of CO2 harm near-surface marine creatures that exoskeletons’ are carbonate based?
Examples are:
Marine animals with shells like crabs, lobsters and clamps. Not forgetting coral reefs.
Basically high concentrations of CO2 will diffuse into the ocean and of which, this diffusion will alter the chemical equilibrium in the ocean, changing the pH value of current 8.7 to slightly acidic which is unfavourable to a variety of marine creatures which inhibits their growth, typically impacting carbonate based marine creatures.
Firstly, we need to know how shells are being formed:
Calcium + Carbonate –> Calcium carbonate (shell)
Ca+ + CO3- –> CaCO3
Secondly,
Carbon dioxide + Water –> Carbonic acid
CO2 + H2O –> H2CO3
and since carbonic acid is a weak acid, it partially ionises in water (the ocean) to dissociate the hydrogen ions: H2CO3 <–> HCO3- + H+
as more carbon dioxide is diffused, the concentration of hydrogen ions (H+) increase resulting to a decrease in pH value to slightly acidic. As more hydrogen ions increase, more hydrogen ions will react with carbonate to form bicarbonate.
CO3- + H+ <–> HCO3 (bicarbonate)
as more hydrogen ions react with carbonate, the concentration of carbonate (CO3-) decrease.
This result to the difficulty of marine creatures forming their exoskeletons’ due to decrease concentration of CO3-
Calcium + Carbonate –> Calcium carbonate (shell)
Ca+ + CO3- –> CaCO3
lastly, as pH value decrease, the dissolution of CaCO3 increase. That means….
Okay! enough of revision for tomorrow’s applied chemistry understanding test.
claud said,
July 10, 2007 @ 12:50 am
o.o wahhh. but tis topic is not tested in the ut3 for applied chem ritess??
Connecting News with National Science Education Standards » Blog Archive » Acid Rain Impacts More Than Just Buildings said,
September 13, 2007 @ 3:46 am
[...] for example. Second, calcium, an element necessary for exoskeleton building, is also harder to sequester. Third, excess nitrogen enables algal blooms, which tend to consume many nutrients, making them [...]
chasity Anderson said,
November 5, 2008 @ 2:59 am
This is really killing a beautiful place and the coral reefs are not going to exist if we dont act fast and stop destroying them!
Plz help to preeserve this beautiful place that is home to many marine animals.
lopraine said,
April 3, 2009 @ 10:37 am
hi it so nice