Subject: Re: [DCHAS-L] Iodine
corrosivity
Date: September 24, 2009 4:09:29 PM
EDT
If the metal trap is galvanized iron, meaning
zinc-coated,
certainly zinc will react spontaneously with I2 in a redox reaction
giving
Zn2+ and iodide, I- . The same thing can happen with aluminum,
with
similar chemistry.
Wayne Wolsey
Professor Emeritus
Macalester College
St. Paul, MN
===
Subject: Re: [DCHAS-L] Iodine
corrosivity
Date: September 24, 2009 5:39:12 PM
EDT
Linda,
Based on the observed results, elemental iodine will
corrode a
metal trap. A knowledge of basic descriptive chemistry, as it was once
taught,
bears this out. There are a couple of things wrong here, not the least
of
which was an incorrect disposal method. A plumber should have been
called to
remove and clean the trap. His visit would be followed by proper
disposal of
the residue. If this couldn't have been done and as a last effort, the
teacher
perhaps should have known that iodine is much more soluble in a
solution of
potassium iodide than in water. On the other hand, is it preferable to
have a
leak with its obvious local contamination followed by proper
disposal of
the residues than it is to discharge a (significant) amount of iodine
and KI
into the sewer system?
Regards,
Ernest Lippert
===
Subject: Re: [DCHAS-L] Iodine
corrosivity
Date: September 25, 2009 10:57:28 AM
EDT
Certainly a possibility. Might be interesting to
perform
surogate experiments w/iodine crystals and pieces of pipe metal. Do
the
experiment w/iodine crystals, w/whatever else might have gone down
this drain,
and then w/iodine crystals plus whatever else might have gone down the
drain.
Bob
