Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Carbon Dioxide Generator
Name: Richard
Status: Educator
Age: 30s
Location: N/A
Country: N/A
Date: N/A


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.

Baldwin



Click here to return to the Engineering Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory