Electrolysis of Aqueous Solutions
Demonstration Notes, Warnings, Safety Information
Strong acid, strong base, heavy metal ions
Hydrochloric acid is a strong acid and its solutions can burn the skin.
Sodium hydroxide (caustic soda) is a strong base. It is corrosive to all tissues and poisonous if ingested.
Tin(II) chloride is toxic and tin(IV) chloride is easily reduced to tin(II) chloride. Nickel and its salts are suspected carcinogens. Ingestion of soluble nickel salts causes nausea, vomiting, diarrhea.
Soluble copper salts are irritating to the skin.
Ingestion of soluble zinc salts may cause nausea, vomiting, purging.
Silver nitrate is poisonous and a strongly oxidizing solution that will stain the skin. It is caustic and irritating to the skin and if ingested can cause severe gastroenteritis that can be fatal.
All water- or acid-soluble barium compounds are highly poisonous.
Lead and its compounds are acutely toxic, especially in young children. Lead poisoning results in anorexia, vomiting, convulsions, and sometimes permanent brain damage.
Nitrate ions are readily reduced to nitrite ions, which are poisonous to small children. The solutions used here are dilute and therefore not as hazardous as if they were concentrated. However, it would be wise to wear protective gloves when handling them. If any of them are spilled on the skin the solution should be washed away immediately with lots of water. Large spills of lead-containing solutions require special cleanup.
These demonstration videos are not meant as tools to teach chemical demonstration techniques. They are meant as a tools for classroom use. Many of the demonstrations present safety hazards or are difficult for an entire class to observe as live demos. If you wish to perform the demonstrations shown here, you should obtain a copy of Shakhashiri's Chemical Demonstrations Vol. 1-4 (1), Gilbert, Alyea, Dutton and Dreisbach's Tested Demonstrations in Chemistry, Vol. I and II (2) and Ellis, Geselbracht, Johnson, Lisensky, and Robinson's Teaching General Chemistry: A Materials Science Companion (3).
Safety information can be obtained from (4).
Credits for the safety information throughout Chemistry Comes Alive!:
Frank W. Darrow, Ithaca College, Ithaca, NY 14850
Kelly Houston Jetzer, University of Wisconsin - Madison, Madison, WI 53706
Gery J. Essenmacher, University of Wisconsin - Madison, Madison, WI 53706
David Phillips, Wabash College, Crawfordsville, IN 47933
John W. Moore, University of Wisconsin - Madison, Madison, WI 53706
Citations
1. Shakhashiri. B. Z. Chemical Demonstrations; University of Wisconsin press: Madison, 1983; Vol. 1.
Shakhashiri. B. Z., Chemical Demonstrations; University of Wisconsin press: Madison, 1985; Vol. 2.
Shakhashiri. B. Z., Chemical Demonstrations; University of Wisconsin press: Madison, 1989; Vol. 3.
Shakhashiri. B. Z., Chemical Demonstrations; University of Wisconsin press: Madison, 1992; Vol. 4.
2. Gilbert, G. L.; Alyea, H. N.; Dutton, F. B.; Dreisbach, D. Tested Demonstrations in Chemistry; Denison University and Journal of Chemical Education: Granville, OH, 1994.
3. Ellis, A. B.; Geselbracht, M. J.; Johnson, B. J.; Lisensky, G. C.; Robinson, W. R. Teaching General Chemistry: A Materials Science Companion, American Chemical Society, Washington, DC, 1993.
4. University of Wisconsin System Administration OSLP EHS MSDS Database; http://www.uwsa.edu/oslp/ehs/msds98-1/ Try this link if you are connected to the web.