Remember, he's trying to collect the gas in a test tube.
Remember, he's trying to collect the gas in a test tube.
Or at about any cheapo discount place. Cells marked "heavy duty" are carbon-zinc rather than alkaline.
Electrolysis is easy only in theory. In practice it takes exotic stuff to make a process that doesn't self-destruct. They used to electrolyze chlorine from molten salt with a puddle of mercury underneath as an electrode. Not something you want to set up in your kitchen.
I am an expert because I own a small salt electrolysis plant where we manufacture chlorine using platinum-ruthenium electrodes for use in my adjacent water utility plant. This is all next to my sod farm. Some would call it just a swimming pool and lawn, but as an engineer I see it for what it really is.
I used to use the graphite rods from the centre of a dry cell when I was a kid.
Be careful with the Chlorine, I was about 8 or 9 and coughed for an hour after I inhaled a test tube full of it.........
If youre half as old as me, pencil leads aren't the same stuff they were when we were kids. :-) ...lew...
There was never any mercury in "dry cells". Carbon-Zinc and Manganaze dioxide etc in the paste. ...lew...
Lew Hartswick fired this volley in news:roednblYPKA66qPUnZ2dnUVZ email@example.com:
Yeah... back then, they were actually made of LEAD!
It was about 30 - 35 years ago and they were Pentel leads IIRC, I haven't tried it with the ones I have at the moment but maybe the next time I'm in the workshop I'll give it a go burning a few and the electrolysis also.
No- he is getting hydrogen. If the cathode was reducing magnesium ions (which is harder than reducing water), the magnesium produced would react with the water to give....hydrogen gas.
It's the oxygen he's not getting, because copper is more easily oxidized than water.
It should also be pointed out that electroplating is also an electrolysis process. Getting good plating is also difficult. For example, cyanide is added to plating baths to make denser deposits. In silver plating, complex ions are formed that greatly reduce the concentration of silver ion Ag+ which actually plates out while keeping total dissoved silver concentration much higher.
The zinc electrode in dry cells is treated with mercury to promote uniform dissolution. I'm not sure you can create a practical dry cell without it. I haven't seen anything that looked like a dry cell in years -- all the cheap consumer batteries I've seen are alkaline cells.
How does mercury do this? If it does so by setting up other electrochemical pairs, why would a quick dip of the zinc into a copper sulfate solution work as well?
At our local 99? store, I am still able to buy dry cells using zinc anodes amd carbon cathodes. The electrolyte seems to be loaded with MgO2.
I only know why it's done, not the mechanism.
Might be time to stock up, before it's too late.
It is not likely to be a problem. The cells marked heavy duty are virtually the same as the original LeClanche dry cells. They certainly are cheaper than alkaline cells.
Hey Leo --
Next time you have a carbon - zinc cell apart would you measure the diameter and length of the carbon rod for me please?
I want to put it into the Circular File:Thanks!
BTW -- another thing which I would suggest that you add.
Get cat litter in the largest containers (the ones which your wife can't lift, and she needs you at the store to get them). Keep her from using them to accept the used (clumping) litter. Wash out the remaining dust before it can set up.
They make excellent containers for grouping like tools.
I have one filled with AMP brand crimpers.
I have another filled with compressed air powered tools and accessories.
Another is used to collect turnings from brass rod to eventually melt down and cast to make other things. (Steel turnings go into a metal garbage can.)
DoN. Nichols wrote: (...)
Thank you, DoN.
Your suggestion is in the Note 2 section regarding housewares. If you wanted to be more specific you could measure and describe the container for us. I guess you have the '40 lb.' white plastic cubical tub with the snap cover and lifting bale. Please let me know if that is the case :)
They have been changing over time.
One is not quite cubical -- it is taller than its square dimensions and it tapers slightly towards the base.
The other is more rectangular, with a convex curve along each edge at the top.
Both are white plastic.
I've also got one full of unsorted screws in boxes and in Ziploc baggies -- at least until I get more sets of plastic drawers in steel cabinets to fill each drawer with a different size and/or length of screw. (I get bags of screws from hamfests, and from the prime scrounger for the local metalworking club.) What we don't take he puts on eBay.
I didn't seem to see a need to list dimensions when they change with the manufacturer's whims. Just go for the large plastic bins of clumping cat litter (assuming that you have a cat to use it) and you will get some very nice rigid containers. They are also good to hold related tools and to sit on when working on something which requires tools and semi long-term access to perform the work. An example was when I was removing and replacing the outdoor fan in the central air conditioning last summer.
And -- the white plastic will gladly accept magic marker annotations as to what is in each individual one -- as they tend to accumulate over time. :-)
"Winston" wrote: Hey Leo --
Circular File" is a very useful collection of data, so I added it to my list of favorites. Hadn't realized that alkaline cells don't use a carbon anode, so it may be hard to find an old D-cell to saw apart, but as soon as I do you'll hear from me.
I remember dissecting carbon zinc cells in my yout but I couldn't tell you the dimensions of the carbon rod with any accuracy at all. A quick check of my cell inventory shows zero of that type and my favorite 'dollar' store was off line this afternoon.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.