Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: angeloposteraro on May 19, 2007, 04:11:31 PM
-
Hello
Firstly to produce the ZnCl2 I diluted 34% HCl, (muriatic acid) at a 3:1 ratio to have a fairly dilute mixture
to this I added strips of zinc metal, from the outside casing of a battery which I polished shiny
my problem is that After adding a great deal of zinc, which fully reacted (14g or so) the solution is still extremely acidic, around 0-1 pH
is there anything I could add to neutralize the remaining acid that wont contaminate the ZnCl2, or a way of extracting the ZnCl2 without making mass amounts of HCl vapors
-
http://en.wikipedia.org/wiki/Zinc_chloride
http://en.wikipedia.org/wiki/Sodium_bicarbonate
My original thought was to neutralize with sodium bicarbonate, but I think that would not give the results you want. Both sodium chloride and zinc chloride are soluble.
From the link at the top – the discussion on purification seems complex for the home setting.
-
thank you for the response,
yes i had tought of sodium bicarbonate, but that would
leave sodium chloride in the solution which is unacceptable,
I guess ill just have to evaporate it,
thank you again
-
I think you will get only the hydrated zinc chloride version using evaporation. Check the link I posted about purification of zinc chloride.
-
Obtaining anhydrous ZnCl2 is not possible in this way. Maybe when you pass dry HCl-gas over the solid, but simply heating, driving off water, will result in splitting off of HCl-gas as well and you end up with a basic chloride at best, or maybe even only ZnO, with chloride as impurity.
-
According to wikipedia, adding zinc to HCl does indeed create ZnCl2
although they say to add zinc until all hydrogen formation ceases, I apparently way underestimated how much zinc was necessary
I intend to make a 6 or so molar solution of ZnCl2, so anhydrous isn't a big issue, my main issue is how to get rid of all that acid remaining in solution.
thank you again for the help.
-
Use excess Zn, filtrate solution after reaction stops.
-
...to this I added strips of zinc metal, from the outside casing of a battery which I polished shiny
Sorry to butt in, but I had to ask. You said the outside casing, but did you mean the inner can?
The reason I ask is, in both alkaline and carbon-zinc batteries, the outer cans are almost always a sheet of nickel-plated steel. Some are zinc plated, but the base metal is still steel. You can verify that with any old magnet.
Now, in carbon-zinc batteries, there's a separate solid zinc can inside that steel outer can, but those aren't sheet zinc, rather, they're a disc that's formed into a can by a press. So, those would be pretty darn hard to cut into strips without a good pair of nippers. :)
Just wanted to clarify for my own curiosity, and also in case you did in fact try this reaction with the outer casing. I'm guessing that would form whatever compounds HCl + steel creates, but not the ZnCl2 you want :)
-Kel
-
use sodium hydroxide or Drano
-
wow thanks to all for the great help,
I am currently leaving it in front of a dehumidifier, which is having a greater effect, I wish to refrain from heating it and decomposing the compound. I am fairly sure it is zinc, there were no inner and outer cans, and it was a carbon zinc battery. I have used the shavings from the can in the water starts a fire reaction leading me to believe that it was in fact zinc.