in chemistry we took a penny and put it into a solution of zinc and sodium chloride. it turned silver, and then we took it out and put it over a flame for about 6 seconds. i know it's not REAL gold, but how does this work??
2007-08-19 16:28:05 · 2 answers · asked by ddcb09 2 in Science & Mathematics ➔ Chemistry
First, the zinc sodium solution reacted to actually form a sodium zincate (Na2ZnO2) by this reaction:
Zn(s) + 2NaOH(aq) = Na2ZnO2(aq) + H2(g)
Second, the copper on the surface of the penny reacted with the zincate ions (ZnO2-2). The Zincate decomposed and reduced to metallic zinc on the surface of the penny.
Third, when the zinc-coated penny was heated, the zinc bonded with the copper to form brass. Brasses with about 35% zinc tend to be yellow in color, so the penny becomes gold in color.
(This technique for the apparent transmutation of zinc in to gold was used by alchemists.)
2007-08-20 09:52:41 · answer #1 · answered by Metallic stuff 7 · 2⤊ 0⤋
I believe what you did was bronze the penny by the addition of the heat you allowed the zinc and copper to blende.
2007-08-20 00:15:58 · answer #2 · answered by Anonymous · 0⤊ 1⤋