The%20bad%20news,%20good%20news%20and%20more%20bad%20news%20about%20elevated%20CO2%20levels%20in%20the%20atmosphere. - PowerPoint PPT Presentation

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The%20bad%20news,%20good%20news%20and%20more%20bad%20news%20about%20elevated%20CO2%20levels%20in%20the%20atmosphere.

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... CO2 comes from car exhaust as the engine burns gasoline making CO2 and water. ... Instead of the source of CO2 being your automobile, it will be yourself. ... – PowerPoint PPT presentation

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Title: The%20bad%20news,%20good%20news%20and%20more%20bad%20news%20about%20elevated%20CO2%20levels%20in%20the%20atmosphere.


1
(No Transcript)
2
  • The bad news, good news and more bad news about
    elevated CO2 levels in the atmosphere.
  • Bad news CO2 contributes to global warming.
  • Good news The ocean is absorbing a good deal of
    this CO2, therefore slowing global warming.
  • Bad news As the excess CO2 dissolves in the
    ocean, the ocean becomes more acidic, therefore
    threatening marine life that uses calcium
    carbonate to build its skeleton or shell. Think
    of coral, lobsters, star fish, and mollusks.

3
  • In experiment 2, we showed that CO2 comes from
    car exhaust as the engine burns gasoline making
    CO2 and water.
  • When CO2 dissolves in water, we showed that it
    becomes carbonic acid. If this water is the
    ocean, this acid threatens the marine animals
    that use calcium carbonate to create their
    exoskeletons and shells.

4
  • There are many ways humans have damaged marine
    life for example, pollution, over fishing,
    dredging, and blasting are the obvious ways.
    Adding carbon dioxide to the atmosphere is a more
    hidden way of harming marine life a way that
    slowly dissolves their bodies.
  • Many sea creatures build the shell or exoskeleton
    using calcium carbonate. This is how it can be
    dissolved
  • First the carbon dioxide combines with water to
    make an acid called carbonic acid.
  • CO2 H2O ? H2CO3
  • Like most acids, the carbon acid releases a
    hydrogen ion (H). Its called an ion because it
    has a charge. In this case, its a plus one
    charge. The hydrogen ion (H) is the calling
    card of acids.
  • H2CO3 ? HCO3- H
  • The hydrogen ion attacks the solid calcium
    carbonate in the shell (or exoskeleton) causing
    the calcium to dissolve into the water. The
    CO32-(called the carbonate ion) combines with H
    to make whats called the bicarbonate ion (new
    name is hydrogen carbonate, which also dissolves
    in the water (ocean). The outcome is the marine
    animal looses its shell or exoskeleton and dies.
  • HCO3- ? H CO32-
  • CaCO3 2H CO32- ? Ca2(aq) 2HCO3-
  • CaCO3 CO2 H2O ? Ca(HCO3)2
  • CaCO3(s) H(aq)? Ca2(aq) HCO3-(aq)

5
H
H
H
H

O
O-
O
O-
O
O-
O
O-
O
O-
C
C
C
C
C
Ca2
Ca2
Ca2
Ca2
Ca2
O-
O-
O-
O-
O-
O
O-
O
O-
O
O-
O
O-
O
O-
C
C
C
C
C
Ca2
Ca2
Ca2
Ca2
Ca2
O-
O-
O-
O-
O-
6
H
H
H
H
Ca2
6

4
Ca2
1
O
O-

H ions
C

2
O
O-

O
O-
O
O-
O
O-

O-
C
5
C
C
C

Ca2
Ca2
O-
Ca2


O-
O-
O-
3


O
O-
O
O-
O
O-
O
O-
O
O-
C
C
C
Ca2
C
C
Ca2
Ca2
Ca2
Ca2
O-
O-
O-
O-
O-
7
H
H
H
H
H
O
H
Ca2
Ca2
O-
O-
O-
C
C
O-
Ca2
O
O
O
O-
O
O-
O
O-
C
C
C
Ca2
Ca2
O-
O-
O-
8
  • To demonstrate that CO2 makes water acidic, we
    will bubble CO2 through water. Instead of the
    source of CO2 being your automobile, it will be
    yourself. Yes, you contribute to global warming
    and to the oceans acidity, too (but to a much
    lesser amount).
  • We will detect the CO2 in two ways. Both ways
    show that the acidity of water increases when CO2
    is added. One way of showing it is by directly
    measuring pH. The other is similar to what we
    did in the car exhaust lab, but this time, you
    will provide the CO2.

9
  • The amount of CO2 that dissolves in water depends
    on the temperature of water. You know this from
    experience. If you open a soda can while warm,
    its likely to spray all over as the CO2
    hurriedly leaves the water to become a gas. If
    cold, more CO2 stays dissolved in the water as
    either CO2 or as H2CO3.
  • We are going to blow into a beaker of ice water
    using some tubing attached to an air stone. The
    concentration of CO2 in air from our lungs is
    about 4 (thats about 4 CO2 molecules (with the
    remaining 100) being water, oxygen, and nitrogen
    molecules), 5 water (H2O) molecules, 15 oxygen
    (O2) molecules, and 76 nitrogen molecules (N2).
    With the car exhaust, CO2 concentration was about
    12 (12 CO2, 75 nitrogen molecules, and 13 H2O.

10
  • CH3(CH2)6CH3 12.5 O2 ? 8CO2 9H2O
  • 12.5 to x 20 to 80 ( 4 x 12.5)50
  • 50 molecules N2 8CO2 9H2O
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