|
Penny in Nitric
Acid
Drop a copper penny into concentrated
nitric acid [HNO3]. Copper nitrate (green) solution
is formed an a red-brown gas, N2O4. Note
the gas is more dense than air. DO NOT
INHALE THE FUMES.
The N2O4 can
be cooled in an ice bath to yield colorless NO2.
This demonstration is based on
that by Bassam Z. Shakhashiri, Chemical Demonstrations: A
Handbook for Teachers of Chemistry, Volume (The University of
Wisconsin Press, Madison, Wisconsin, 1989), pp. . The
explanation is much more in-depth in this textbook, and the
demonstration is far more impressive in person; I would highly
recommend the purchase of this extraordinary set of books for
anybody interested in this or other chemical demonstrations.
As with any demonstration, be sure to follow the directions very
carefully and observe all applicable safety precautions. This
web site does not purport to be a site designed to convey directions
for chemical demonstrations, and is not liable for any injuries or
damages sustained by those who would attempt to re-create this
demonstration without proper training, supervision or instructions.
Concepts: Smog
formation, Acid Rain, Dimers
Time Required: 15
minutes
Chemicals Needed: copper
penny, nitric acid [HNO3]
|
