Focus on the Nation One small piece of CO2 affecting the oceans

1
Focus on the Nation One small piece of CO2
affecting the oceans

• How to make salt water and saturation
• How to make soda and Henrys Law
• Acid/base equilibria and sea shells
• Conclusions

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I. How to make salt water and supersaturation

• What happens when I add salt to water and stir?
• Will I be able to do this forever?
• Some Definitions
• Unsaturated solutions- a solution capable of
  dissolving more of a solute.
  
• Saturated solution- a solution that has dissolved
  the maximum amount possible of the solute.

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I. How to make salt water and supersaturation

• What does this have to do with our oceans?
• Our oceans are saturated with CaCO3 (calcium
  carbonate)
  
• This discourages the CaCO3 in shells from
  dissolving in the water environment keeps
  shells solid.

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II. How to make soda and Henrys Law

• To make soda we need to get a high level of CO2
  in it.
  
• Henrys Law- CgkPg The solubility of a gas in
  solution is equal to the partial pressure of the
  gas over the solution and the Henrys Law
  constant (which is different for each gas over
  each different solvent)

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II. How to make soda and Henrys Law

• Simply put to get CO2 into soda, bottlers put a
  pressure of slightly over 1.0 atm of CO2 over the
  liquid. (In the air the pressure of CO2 is closer
  to 0.0003atm)
• What happens to the CO2 concentration above the
  soda once the can of soda is opened? What
  happens to the concentration of CO2 in the soda?

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II. How to make soda and Henrys Law

• What does this have to do with the oceans?
• Combustion of fossil fuels has lead to a much
  higher concentration of CO2 in the atmosphere.
  
• If we look at all the CO2 produced, only about
  50 of human sources is ending up in the air, the
  rest is being absorbed by land and oceans.
  
• The increase of CO2 in our atmosphere is acting
  to a smaller degree like the CO2 bottlers put
  artificially above soda- it is leading to higher
  levels of CO2 in the ocean.

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III. Acid/base equilibria and sea shells

• Some reactions go from reactants to products and
  stop. Others go back and forth establishing and
  equilibrium
  
• One of the important equilibrium reactions is
• H2O CO2 H2CO3 H HCO3-
• The H acts as an acid to lower pH, inc CO2 ?
  form more H, dec. CO2 ? remove H
  

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III. Acid/base equilibria and sea shells

• The egg

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III. Acid/base equilibria and sea shells

• What does this have to do with the oceans?
• Added CO2 to the water increases the H in the
  oceans. The pH of the oceans is slowly
  decreasing (it is still above 7, (basic) but
  getting closer to 7.
• Effect H is reacting with CaCO3 to decrease
  the concentrations in the ocean leading to
  difficulty of forming and retaining shell
  structures. This is endangering any sea
  creatures that use CaCO3 in their shell
  structures. For some creatures this has been
  proven through studies, for others it is
  theorized, but still being investigated.

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IV. Conclusions

• Some of our CO2 emissions are ending up in the
  oceans
  
• This is altering the pH of our oceans
  (debasification/acidification)
  
• Animals with CaCO3 (calcium carbonate) in their
  shells will be less able to survive under these
  new conditions because their shells will dissolve
  or fail to form properly.