The Vespiary

The Hive => Newbee Forum => Topic started by: officer_murphy on December 11, 2003, 05:03:00 AM

Title: aluminum foil in place of Zn?
Post by: officer_murphy on December 11, 2003, 05:03:00 AM

can aluminum foil be used in place of zinc in Zn/HCl reductions?

Title: no nice try tho ;-)
Post by: Antibody2 on December 11, 2003, 10:46:00 AM

no

nice try tho ;)

Title: but iron
Post by: Organikum on December 15, 2003, 04:58:00 AM

can replace Zn quite often.

Title: Sort of
Post by: methymouse on December 15, 2003, 07:28:00 PM

You might be able to use zinc deposited on aluminum foil.  I found a 17% zinc chloride solution sold as something like "Glass flux" at a hobby store.  I think it's for soldering onto stained glass.

Here's how you can make the "galvanized aluminum foil"
150 ml of a 17% ZnCl2 solution, and 2ml 31% HCl were placed in a 250ml beaker.  The solution was heated for several hours at 90^oC, and small strips of aluminum foil were added slowly until all blue color had disappeared from the solution.  Slow hyrdogen gas evolution was observed.  This reaction is nowhere nearly as exothermic as Urushibara nickel, and doesn't seem to take place at all at temperatures below 45^oC, so perhaps the aluminum could be added more quickly.  You should be able to get rid of the aluminum, and get a fine powder of Zn/alumina by washing with a 20% NaOH solution.

I presume that these foil strips should work as is in most cases where zinc is called for (eg. Zn/carboxilic acid reductions), unless the aluminum would screw something up.

Best of luck!

-MethyMouse