Author Topic: Zinc Chloride from OTC acid  (Read 746 times)

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Chewbacca

  • Guest
Zinc Chloride from OTC acid
« on: October 16, 2003, 09:06:00 AM »
SWIC remembers seeing some acid in the hardware store that contained zinc chloride and was in a black bottle... he had a brief peer at it but did not purchase the product, and since then that particular store has closed down...

SWIC cant remember for the life of him the OTC name of the acid or its uses.... could any other bees please remind him?


Ziqquratu

  • Guest
Re OTC zinc chloride
« Reply #1 on: October 16, 2003, 10:31:00 AM »
If memory serves, zinc chloride solutions are used as flux for soldering, although they don't tend to be that concentrated (I think most of the ones I've ever seen were only around 4-5%).  This may not be what you saw, but it is a potential source if you're desperate.

stratosphere

  • Guest
well zinc chloride definitly not a watched...
« Reply #2 on: October 17, 2003, 03:49:00 AM »
well zinc chloride is definitly not a watched chem, but if you don't want to go through the trouble of mail order here is a tip...newer US pennies are copper plated zinc, use a file to scratch off a bit of copper, throw her in some HCl, wait a day or so, and viola! ZnCl2(aq)
the copper should not dissolve in HCl so there will just be some copper flakes to filter out.

Chewbacca

  • Guest
Cheers
« Reply #3 on: October 17, 2003, 08:19:00 AM »
Nice tip about the coins, thanks. SWIC will look into the acid, 4% is enough for SWICs purposes and the 400ml of 500ml bottle he once saw was only about $8AUS. i have a feeling aussie coins are composed of a little nickel! if HCl was added to these, would it react to form NiCl2 in the same fashion?

cheers ;D


halfkast

  • Guest
Chewy just go to any coin shop then bee.
« Reply #4 on: October 17, 2003, 01:54:00 PM »
Chewy just go to any coin shop then bee. Forget the acid.

From what year are US pennies zinc?


Chewbacca

  • Guest
Batteries?
« Reply #5 on: October 17, 2003, 02:00:00 PM »
There are batteries which contain zinc chloride as the electrolyte. Would this be suitable to use?

Also, SWIC carried out an experiment. An ozzy 5c coin (The 5c, 10c, 20c and 50c coins are made of 75% copper and 25% nickel) was dropped in a little dilute HCl and boiled away on a hotplate for 10 mins. As the water level dropped and the  solution heated, bubbles appeared on the surface of the coin and the HCl turned a very dark purple/blue colour. The acid was boiled off, the beaker cooled and cold water added. It appears that the surface of the coin was eaten away by the acid. The aussie 5c coin looks like this (

http://www.ramint.gov.au/making_coins/coin_designs.cfm

) and that silvery metal exterior was corroded by the acid and remained as an insoluble solid in the water. Whats left is a copper coloured coin. So im assuming that the acid removed the nickel plating on the copper coin. Why didnt it react to form NiCl2? Should SWIC remove the nickel plating like this and then leave the nickel bits in a conc HCl solution for several days to yield NiCl2?

ps- yes i know it is fucking sad to bee scrounging around for reagents like this... sorta funny... :P


stratosphere

  • Guest
From what year are US pennies zinc?
« Reply #6 on: October 17, 2003, 09:13:00 PM »
From what year are US pennies zinc?

according to

http://www.1728.com/projects.htm

the switchover to copper plated zinc occured in 1982.

after your friend finishes there little cooking project, they will need this site

http://www.enchantedlearning.com/math/money/coloring/penny.shtml


a print out of a penny they can color in with their crayons! ;D

Polverone

  • Guest
an easier way
« Reply #7 on: October 24, 2003, 07:16:00 AM »
Pour HCl over your zinc-core pennies and add a little H2O2. The copper shells will be partially dissolved, at least enough to pierce them. The zinc will plate the copper out again (in a rather fluffed-up mass) as it dissolves in the acid.

ZnCl2 solutions prepared this way were good enough for making porous zinc foil and crude powder, via reaction with Al foil. However, actually obtaining anhydrous (or close to it) ZnCl2 by heating solutions seemed impossible for me to achieve.


dwarfer

  • Guest
anhydrous ZnCl2
« Reply #8 on: October 27, 2003, 10:36:00 PM »
Yeah, I tried to dry some ZnCl2 that was not stored tighly enough (although the lid was on tight,?? some moisture definitly weaseled it's way in..

At a 30" vacuum @ 110C after two days??

Still a liquid, and rusting the fuck out of the steel
vacuum oven, so i said "fuck it"..


lugh

  • Guest
Zinc Choride Preparations
« Reply #9 on: October 28, 2003, 02:19:00 AM »
From Thorpe's:

This compound appears to have first been prepared and described by Glauber in 1648, who obtained it as a thick oil, by heating sal ammoniac with calamine, zinc carbonate. Later methods of preparation involved the action of chlorine on the heated metal and the reaction of calcium chloride on heating with zinc sulphate.
Commercially it is commonly prepared by the action of hydrochloric acid on a wide variety of zinciferous materials, ranging from scrap zinc to zinc ashes and galvanisers' dross. The zinciferous material is placed in a cast-iron, stone, or wooden vessel containing hydrochloric acid. The solution so obtained is warmed to 70-75°C., and neutralised with sodium carbonate or sodium hydroxide solution, and manganese and iron are precipitated with chlorine or sodium hypochlorite. Zinc dust is added to precipitate copper, lead, and nickel. Details of the purification may vary considerably, depending on the relative amounts of impurities present.
The purified solution is boiled until the desired concentration is reached; a little pure hydro­chloric acid may be added to dissolve any basic salt formed; if the evaporation has been carried far enough the mass will solidify on cooling and is agitated to facilitate breaking up and subse­quent packing in airtight drums.
Many other methods of preparation have been proposed, but few have been used to any great extent.
Pure anhydrous zinc chloride can be obtained on a small scale by dissolving high-purity zinc in hydrochloric acid and evaporating in an atmo­sphere of hydrogen chloride gas.Zinc chloride may be obtained as a white, vitreous, extremely hygroscopic mass by allow­ing a melt to solidify, as white octahedral or prismatic crystals by allowing a highly con­centrated aqueous solution to stand at room temperature, or as a white powder by evaporating an aqueous solution.
Zinc chloride is extremely toxic. Its physical properties are difficult to determine owing to the hygroscopicity of the anhydrous salt, which has led to widely different values being reported for some properties, notably the specific gravity and melting-point. The figures 2.91 for sp. gr. (Baxter and Lamb, Amer. Chem. J. 1904, 31, 229) and 275°C. for m.p. are generally accepted. It is very difficult to remove the last traces of water from the solid.
Zinc chloride melts to a clear, colourless, highly refractive liquid, and boils at 720°C., distilling without dissociation up to a tempera­ture of at least 900°C. (Meyer and Meyer, Ber. 1879, 12, 1195).
The so-called anhydrous form still contains appreciable amounts of water and passes very readily to a hydrated form at room temperature. In addition to its high water-solubility, zinc chloride is freely soluble in many organic liquids such as alcohols, esters, ketones, ethers, furfurals, amides, and nitrites.


From Brauer's:

Very pure, anhydrous ZnCl a is prepared by treating Zn with dry HCl at 700°C in a quartz boat placed in a tube of high-melting glass. At this temperature, the formation and sublimation of ZnCl proceed at sufficiently high rates. The sublimed chloride is collected in a section of the tube which is kept cool for this pur­pose. Temperatures above 700°C should be avoided, since en­trainment of zinc vapor with the chloride may result, a phenomenon recognizable by the appearance of acolor inthe otherwise colorless sublimate. For additional purification, the chloride may be resub­limed in a stream of HCl.

II. The same reaction can be carried out in anhydrous ether. Ether and excess HCl are removed on a steam bath (vacuum).

A 6.7% solution of CuCl in pure, dry acetonitrile; (distilled several times over P205) is electrolyzed at room temperature with a Pt cathode and a Zn anode (voltage across the terminals is 12 v.). The electrolysis proceeds under a blanket of absolutely dry Na. The reaction is complete when a gray coating of Zn is observed on the Cu deposited at the cathode. The solvent is evaporated in vacuo, and the acetonitrile solvate of ZnCia is converted into the unsolvated salt by careful heating. Yield 96­-98%.
If the appropriate copper salts are used, the process may also be employed for the preparation of ZnBr2 and ZnI2, and by sub­stituting a cadmium anode for the zinc electrode, CdBra and CdI3 may be prepared.
Zinc chloride exists in three different crystal modifications. Details on the preparation and the structure of the pure individual modifications are given by H. R. Oswald and H. Jaggi [Helv. Chim. Acta 43, 72 (1960)].

PROPERTIES:

Colorless, highly hygroiscopic, small crystals. M.p. 313°C, b.p. 732°C; d (pycn.) 2.93. Solubility per 100 ml. of H20: (0°C) 208 g., (20°C) 367 g. (d 2,08), (100°C) 614 g. Crystallizes in the anhydrous form only above 28°C. Soluble in methanol, ethanol, ether, acetone and other organic solvents.

REFERENCES:
I. 0. Hoenlgschmid and M. von Mack. Z. anorg. allg. Chem. W, 366 (1941); for apparatus, see 0. Hoenigschmid and F. Wittner. Ibid. 226, 295 (1936).
13. R. T. Hamilton and J. A. V. Butler. J. Chem. Soc. (London) 1932, 2283.
Ill. H. Schmidt. Z. anorg. allg. Chem. 221, 305 (1953).


From Encyclopedia of Organic Reagents

Zinc Choride may be purified by refluxing 50 g in 400 ml of dioxane in the presence of zinc dust, then filter hot and cool to precipitate the purified zinc chloride. Also, anhydrous material may be sublimed under a stream of dry HCl, followed by heating in a stream of dry nitrogen to 400°C

:)  ;D  :)


halfkast

  • Guest
microwave?
« Reply #10 on: October 28, 2003, 09:00:00 AM »
I think I'd put a small sample in the microwave and see how that goes.

I'd use some paper towel placed above it to see if it was working and if anything other than water was being vaporised.


roger2003

  • Guest
Zinc Chloride
« Reply #11 on: October 28, 2003, 01:38:00 PM »
From Kirk-Othmer


Zinc chloride melts at 275°C, boils at 720°C, and is stable in the vapor phase up to 900°C. It is very hygroscopic, extremely water-soluble, and soluble in organic liquids such as alcohols, esters, ketones, ethers, amides, and nitrides. Hydrates with 1, 1.5, 2.5, 3, and 4 molecules of water have been identified and great care must be exercised to avoid hydration of the anhydrous form. Aqueous solutions of zinc chloride are acidic ( for 6 M) and, when partially neutralized, can form slightly soluble basic chlorides, eg, ZnCl2·4Zn(OH)2 [11073-22-6] and Zn(OH)Cl [14031-59-5]. Many other basic chlorides have been reported (58).
Anhydrous zinc chloride can be made from the reaction of the metal with chlorine or hydrogen chloride. It is usually made commercially by the reaction of aqueous hydrochloric acid with scrap zinc materials or roasted ore, ie, crude zinc oxide. The solution is purified in various ways depending upon the impurities present. For example, iron and manganese precipitate after partial neutralization with zinc oxide or other alkali and oxidation with chlorine or sodium hypochlorite. Heavy metals are removed with zinc powder. The solution is concentrated by boiling, and hydrochloric acid is added to prevent the formation of basic chlorides. Zinc chloride is usually sold as a 47.4 wt % (sp gr 1.53) solution, but is also produced in solid form by further evaporation until, upon cooling, an almost anhydrous salt crystallizes. The solid is sometimes sold in fused form.

The fumes of zinc chloride are highly toxic and can damage mucous membranes and cause pale gray cyanation. It can also ulcerate the skin of workers using it as a soldering flux or those handling wood impregnated with it (59).
The largest use of zinc chloride in the United States is in wood preservation, fluxes, and batteries . Zinc chloride solution dissolves vegetable fiber and is widely used in mercerizing cotton (qv), swelling fibers, as a mordant in dyeing, parchmentizing paper, etc . It dissolves metal oxides and is used as a flux, especially in galvanizing . Zinc electroplating is often done with a chloride bath ( ELECTROPLATING). In medicine, it is used in antiseptics, deodorants, dental cements, and disinfectants (qv). Zinc chloride solutions preserve wood and textiles and are used in adhesives (qv) and embalming fluids ( TEXTILES). Other uses are in organic synthesis, eg, in the preparation of methyl chloride and diethylzinc, as a dehydrant, in rubber vulcanization, and in oil refining.

58 .J. W. Hoffman and I. Lander, Aust. J. Chem. 21, 1439 (1968).
59. N. L. Sax, Dangerous Properties of Industrial Materials, 5th ed., Van Nostrand Reinhold, New York, 1979, pp. 1100-1104.


dwarfer

  • Guest
i'll be damned
« Reply #12 on: October 29, 2003, 01:49:00 AM »
Who woulda thunk it was such a bitch to make?

Last time I used it was ala Wizard X's technique
to make chloro ephedrine.

I used some sharp nosed pliars to break off chunks for weight:  even as new it was UNdry..

Now All I have is that viscous brown oil, and have no idea
what equivalents would be measured out.