Hamilton
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Posts: 19
Registered: 24-11-2009
Location: Minas Tirith, Middle-earth
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sulfur color
hi,
this is my firts post here, i am been reading this forum for some time now and decided to register, i am studying in physics (don't knw my level in
english term, second year in university now). i have always been intereste in chemistry too but didn't get any advance course.
the last month a saw a video on youtube of a man plating very thin layer of sulfur (in the form of silver suflide) on a silver plate to create rainbow
color. his plating solution was water with NaOH and elemental sulfur wich seem to be soluble in water NaOH solution. I try to reproduce this mixtur
with success and decided to test (qualitatively) by titrating with vinegar until the sulfur is not soluble anymore and precipitate because of lack of
NaOH (or is it the ph that give solubility not NaOH itself). After some time i drop the deciding droplet of vinegar and everything turn white instead
of yellow as i would tought, it start smelling H2S or something like that so i put it outside the house. the next day all the white powder has moved
to the bottom of the flash. since i don't know any sulfur and sodium insoluble salt, the powder must be sulfur and may be white because of small
particle size.
after this test lot of the original yellow solution was left in two sealed plastic pills box and left over for weeks. I check them recently and the
solution as turn almost transparent, incolor and inodor. When mixed with CuSO4, a black precipitate of CuS is still formed. there was no bubble of
hydrogen or oxigen when the color was changing
xNaOH + yS + zH2O = ??? + 0O +0H +0H2S
what is the unknown compound ?
thx
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gsd
National Hazard
Posts: 847
Registered: 18-8-2005
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@Hamilton
Welcome to the forum.
Just try to go thru' this PDF posted on this very forum some time ago. I think you will get your answers.
www.sciencemadness.org/talk/files.php?pid=42590&aid=716
gsd
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