You must of course collect it and bring it to the proper disposal facility ;-)
Or you could just dump it down the drain, we are talking about minute
amounts for this analysis.
In the end you must wash boards too, which leaves you with lotsa
slightly dirty water. You can hardly drink it.
The solution to pollution is dilution :-)
ST
On Dec 14, 2007 6:29 PM, persnickimmon <dexter.kline@...> wrote:
> Not to thread-jack, but what is the proper method of disposal of the
> CuOH precipitate following this procedure?
>
>
> --- In Homebrew_PCBs@yahoogroups.com, YD <yd_br@...> wrote:
> >
> > Your method is what works for me, except I use the
> > solution itself as an indicator.
> >
> > First off, mix 40 g NaOH to 1 liter of water to make a
> > 1 molar standard solution (even 4 g in 100 ml will
> > last you a lifetime).
> >
> > Place 10 drops of CuCl2 in a test tube or other
> > similar container. Add some water to increase the
> > volume a bit, quantity isn't critical but don't make
> > it too transparent. Double or triple is fine.
> >
> > Fill the dropper with the standard solution (wash it
> > off first). Add it to the test tube one drop at a
> > time. A darkish cloud forms where it hits. Shake the
> > tube to dissolve it. As you keep dropping it will
> > start forming tiny white flakes. Keep shaking it. Stop
> > when the flakes refuse to dissolve. Divide by 10 (or
> > however many drops of CuCl2 you used) to find the
> > molarity.
> >
> > The NaOH at first reacts with the HCl forming NaCl
> > and H2O. The initial darkish cloud is due to a
> > momentary formation of CuCl which reacts with the
> > remaining HCl back to CuCl2. When the HCl is exhausted
> > the reaction forms CuOH which is only weakly soluble
> > making it cloudy.
> >
> > As for density you can weigh 100 ml in a tared
> > container and multiply by 10.
> >
> > You can also use a tared container of unspecified
> > volume by first weighing the solution and then the
> > same volume of plain water. Divide the former by the
> > latter to find the density directly.
> >
> > The methods above are ballpark only, but should be
> > within 10% tolerance. CuCl2 itself is pretty tolerant
> > about variations as long as they stay within limits.
> >
> > - YD.
> >
>
>
>
>
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