Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/5/84; site kitty.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!gamma!epsilon!zeta!sabre!petrus!bellcore!decvax!genrad!panda!talcott!harvard!seismo!rochester!rocksanne!sunybcs!kitty!larry
From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: net.analog
Subject: Re: Re: Re: Rosin flux hard to find?
Message-ID: <683@kitty.UUCP>
Date: Fri, 3-Jan-86 17:23:06 EST
Article-I.D.: kitty.683
Posted: Fri Jan  3 17:23:06 1986
Date-Received: Mon, 6-Jan-86 03:04:40 EST
References: <789@brl-tgr.ARPA> <652@kitty.UUCP> <218@ski.UUCP>
Distribution: net
Organization: Recognition Research Corp., Clarence, NY
Lines: 30

> I don't know where this fellow shops, but as far as I know, plumbers ALWAYS
> use acid fluxes.  These include liquids or pastes with zinc chloride as the
> active component- it yields hydrochloric acid.
>
>		Zn(Cl)2 + 2*H2O  <--->  Zn(OH)2 + 2*HCl
>					weak      strong
>					base      acid
> David Robins, M.D. 

	The above equation is NOT the hydrolysis reaction for zinc chloride,
and is furthermore not reversible as you have implied.  Zinc hydroxide is
amphoteric, virtually insoluble in water, reacts only with STRONG HCl to form
zinc chloride, and is NOT the hydrolysis product of zinc chloride.
	The actual reaction is:

		Zn(Cl)2  +  H2O  <--->  ZnO  +  2(HCl)

	The above reaction proceeds to the right until equilibrium is achieved,
resulting in a pH of around 4.0 in aqueous solution, along with a significant
concentration of zinc oxide being present in solution.  A pH of 4.0 is only
weakly acidic.  Zinc chloride therefore does not remain as a pure solute in
aqueous solution.  Lest you doubt my word on the hydrolysis of zinc chloride,
you may check it out in the Merck Index 9th Ed.

==>  Larry Lippman @ Recognition Research Corp., Clarence, New York        <==
==>  UUCP    {decvax|dual|rocksanne|rocksvax|watmath}!sunybcs!kitty!larry  <==
==>  VOICE   716/741-9185                {rice|shell}!baylor!/             <==
==>  FAX     716/741-9635 {G1, G2, G3 modes}    duke!ethos!/               <==
==>                                          burl!gladys!/                 <==
==>  "Have you hugged your cat today?"           ihnp4!/                   <==