Question:
How Do you construct a carbon dioxide generator for use
to demonstrate the needs of plants require a higher concentration of co2
then the planet can sustain?
Replies:
Several generators come to mind depending on your resources and whether the
supply needs to be continuous vs. interrupted.
1. If you have a source of "dry ice", its sublimation produces CO2
directly. The gas will be very dry however, if that is an issue.
2. Baking soda, NaHCO3, which is readily available can be dissolved in
water even to saturation. Then drop some diluted HCl and CO2 will be
evolved. HCl is available at hardware stores of building supply stores under
the archaic name muriatic acid, but it's just HCl. Dilute it before adding
dropwise to the baking soda so that the evolution of CO2 stays under control
and not too much heat is evolved. You need not dissolve the baking soda, but
doing so gives you more control.
3. Calcium carbonate sold as calcium supplements in the pharmacy will do the
same thing when HCl is added.
4. If you make friends with the local fire extinguisher re-filler you might
be able to borrow a cylinder of CO2. Of course here you will need a pressure
reducing valve.
The key is to keep the reaction under control so that you don't transpire
any HCl vapors into the test system. Vinegar can be substituted for HCl but
of course you are going to get some acetic acid vapor too.
VC
A human is almost a perfect CO2 generator. What exactly do you mean plants
require a higher CO2 level than the planet can sustain though, most likely a
plant would die in 100% CO2 just as a human would die with only 100% oxygen,
and the greenhouse effect is a perfect example that the co2 level is
increasing.
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