[mafiaparty303]

So I was making some Zinc Chloride with HCl and Zinc in a small 50 ml flask, after i took out the large chunks of the the zinc with ZnCl coating I left the flask outside with black specks of ZnCl on the sides, to my surprise today i went outside and most of the Zinc salt has turned that torquoise green that you see when Copper oxidies on roof shilings and such... what could this possible be?

[constant thinker]

Firstly, Zinc chloride is toxic I believe. So be wary.

Secondly, Zinc usually takes a +2 charge so it is ZnCl₂.

I think zinc chloride is hygroscopic. Odds are it's a hydrate. When you first made zinc chloride what you saw was anhydrous. Now it has absorbed water an has become a hydrate.

Just so you know, when you dehydrate a hydrate often a time it will change color. Take for example copper (II) sulfate. It usually exists as a pentahydrate, and appears a blue color. When you drive off the water to form anhydrous copper (II) sulfate, the crystals become a gray/off white color.

[Edit] Just thought I would add that I have no experience with zinc chloride, I'm just acting on the fact that one of the differences between an ionic compound as a hydrate and anhydrous tends to be the color. Could you perhaps provide a picture?

[mafiaparty303]

sure I'll probably have one tommorow. If anything i think it has become anahydrous now, since the powdered or flaked pieces in the HCl H2O solution were black so im guessing its the reverse. Ill get a picture us ASAP.

[Yggdrasil]

Since zinc ions are d¹⁰, zinc salts generally are not colored since there are no d-->d transitions.

[billnotgatez]

http://en.wikipedia.org/wiki/Zinc_chloride

[woelen]

Zinc chloride is white, both the hydrated and the anhydrous form.

Under the given conditions you will NOT get anhydrous zinc chloride. Anhydrous zinc chloride is VERY eager to react with water. If you bring that in contact with water, then a lot of heat is produced and fumes of HCl may escape due to hydrolysis.

The colors you had were due to impurities, other explanations are not likely to be correct.

making anhydrous zinc chloride from the hydrate hardly is possible. If you heat the hydrated salt, then you'll notice that it does not only loose water, but also HCl, and some basic zinc chloride/oxide is formed.

[mafiaparty303]

ok, so its because of impurities, since on the Muriatic acid bottle it says %29 HCl and 71% Inert Ingredients ( I don't remember if its inert but ill go check later) so it dosnt say, HCl and H2O

[woelen]

Good hydrochloric acid is colorless. The muriatic acid from hardware stores frequently is somewhat yellow/green. I have a bottle of 37% HCl and it looks like water.

But the metal could also contain impurities. If you use zinc for construction/building purposes, then don't expect high purity material. It usually contains remains of iron, cadmium, chromium, and possibly copper.

[mafiaparty303]

I used melted zinc from pennies so it probably contains some copper or possible bronze, but i didnt see any orange/red copper after the reaction had taken place.

[joeflsts]

Firstly, Zinc chloride is toxic I believe. So be wary.

Secondly, Zinc usually takes a +2 charge so it is ZnCl₂.

I think zinc chloride is hygroscopic. Odds are it's a hydrate. When you first made zinc chloride what you saw was anhydrous. Now it has absorbed water an has become a hydrate.

Just so you know, when you dehydrate a hydrate often a time it will change color. Take for example copper (II) sulfate. It usually exists as a pentahydrate, and appears a blue color. When you drive off the water to form anhydrous copper (II) sulfate, the crystals become a gray/off white color.

[Edit] Just thought I would add that I have no experience with zinc chloride, I'm just acting on the fact that one of the differences between an ionic compound as a hydrate and anhydrous tends to be the color. Could you perhaps provide a picture?

You should be wary of any chemical.  It isn't so much toxic as it is corrosive.  Did you know that it is used in Fabreeze?

Joe

[joeflsts]

Firstly, Zinc chloride is toxic I believe. So be wary.

Secondly, Zinc usually takes a +2 charge so it is ZnCl₂.

I think zinc chloride is hygroscopic. Odds are it's a hydrate. When you first made zinc chloride what you saw was anhydrous. Now it has absorbed water an has become a hydrate.

Just so you know, when you dehydrate a hydrate often a time it will change color. Take for example copper (II) sulfate. It usually exists as a pentahydrate, and appears a blue color. When you drive off the water to form anhydrous copper (II) sulfate, the crystals become a gray/off white color.

[Edit] Just thought I would add that I have no experience with zinc chloride, I'm just acting on the fact that one of the differences between an ionic compound as a hydrate and anhydrous tends to be the color. Could you perhaps provide a picture?

You should be wary of any chemical.  It isn't so much toxic as it is corrosive.  Did you know that it is used in Fabreeze?

Joe

Yes, the penny you melted isn't pure zinc and is most likely the reason for your comtamination.

Joe

[mafiaparty303]

ok thanks for the help all