[acecase]

First of all, hello and thank you all. This is my first post, but I have been reading and learning a lot from this forum. There are a lot of really good chemist here, and the rest of us benefit a lot from the knowledge and experience that you all share.

My question is regarding a precipitant which I believe to be Zinc; at least that was my intention.

I obtained Zinc metal initially by melting it out of pennies. I then dissolved it in HCl (31.45% Muriatic) and filtered off the copper and miscellaneous other contaminants. At this point I assume I have a ZnCl solution. I then made up a rough (unknown molarity) solution of NaOH and combined the two solutions. Immediately a white precipitant was produced.

I assumed, that what happened was a single displacement (ZnCl + NaOH -> NaCl + H2O + Zn), but I couldn't get that to balance.

My theory (if my amateur guess could be called such) is that one of three things has happened.

a) I was wrong to start with and my ZnCl wasn't ZnCl but HCl + Zn. I doubt this though because a lot of H went gaseous in the initial reaction.
 
b) 2ZnCl + 2NaOH -> 2NaCl + H2O + 2ZnO
or
c) 2ZnCl + 2NaOH -> 2NaCl + H2O + 2Zn + O(g)

In short (too late), I would like to keep the white powder precipitant for later use, but I can't be sure how to label it.

I would appreciate it if anyone could tell me what it is (or should be based on my description), and even more so if someone could tell me a cheap easy way to test it. I really hope it is elemental Zn, but I don't know how to know for sure. I have no way to measure up to 400+C melting point so that isn't an option.

For the record I'm leaning toward (b) above which would make it Zinc Oxide, but I'm sure the majority of you would know with more certainty.

Thanks in advance,
Harley

[UG]

Surely it's zinc hydroxide

ZnCl₂ + 2NaOH  Zn(OH)₂ + 2NaCl

[acecase]

So HCl + Zn -> ZnCl₂ ?

Thank you

[UG]

So HCl + Zn -> ZnCl₂ ?

Yep  

-----

Of course, don't forget the hydrogen

2HCl + Zn -> ZnCl₂ + H₂

[acecase]

Not exactly a useful synthesis, but my first personal discovery and a great learning experience.

I'm figuring out that I have to learn everything twice. Once I hear it and begin to understand it. Then after I forget to apply it and mess something up. I should have known that Zn would bond with 2 Cl and I wouldn't have confused myself.

Thanks for the help.