Author Topic: too much sodium carbonate?  (Read 701 times)

Offline bcboy

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Re: too much sodium carbonate?
« Reply #15 on: April 23, 2020, 06:11:02 AM »
yeah, RedDogJT, I was actually known as the "Analog Dog" in my old mixed-signal CMOS IC design group.

I like analog gauges where precision is not an issue. I am kinda retro too I guess. Enclosed is a picture of my lab bench at home, :-)

rogerw

ps - btw those meters on top are VTVMs (vacuum tube voltmeters)  largely from the late 1940s and 1950s in terms of state of the art design.......

And where is Tesla when we need him?


Yes thanks for taking the time to post your pictures. :D
:D One day at a time.

Offline rogwhat53

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Re: too much sodium carbonate?
« Reply #16 on: April 23, 2020, 05:41:41 PM »
Back to the original point of this thread, which is some kind of light colored fine precipitate forming on the silver leaf anode during the second hour of a two hour run (10-12 drops of 2M Na2CO3 electrolyte, 50/50Karo reducer added up front, 150-155degF throughout, 5mA constant current @ >12Vdc across cell).

I am supposing that this must be too long to cook Karo at that temp and it is the precipitate that clouds the product, but I really do not know. The solution seems so far to be 1) lower the temperature of processing, and, 2) dont't add the Karo reducer till the beginning of the second hour.

The first hour at 5mA, for 20ppm, is not clouded and is fine. But the second hour for 40ppm produces a clouded product if the temp is high or if I put the reducer in at the outset.

So, 140degF and reducer at the beginning of the second hour worked although there was just a hint of the cloudy precipitate forming. 120deF and reducer at the second hour seemed to work well.

BTW, cfnisbet and Gene have convinced me to try maltodextrin so I have ordered some CarboGain. I am also toying with the idea of a mixer.

I am still open to suggestions of what this light colored precipitate might be.......

rogerw