[KB3BYT]

I found a home brew battery in a 1920s radio magazine:

that specifies to use sulfate of zinc and acidulated water and saturated copper sulfate crystals.

I have not done any chemistry since high school in 1975.
so I looked up on the internet ZINC SULFATE
and
ACIDULATED water.
and found on the web and it says we can buy 220mg zinc sulfate capsules...to eat.
huh?!!??
edible batteries?

Zinc Sulfate (220mg) - 100 Capsules
Zinc sulfate is an inorganic compound and dietary supplement. As a supplement it is used to treat zinc deficiency

but hey...it did say "OR"
and when I look up acidulated water it said

wiki:
Acidulated water is water that an acid has been added to it, usually lemon juice, lime juice or vinegar. Citric acid and ascorbic acid can also be used.

 Acidulated water can be made by combining 1.5 tablespoons vinegar or 3 tablespoons lemon juice.

sooooo.. OK... this doesn't sound real toxic or dangerous to show and tell kids battery chemistry....

AND THEN
there is the saturated copper sulfate....
which is readily available at the hardware store
 ROOT KILL copper sulfate pentahydrate 99%
with instructions to grow the crystals
OR
just buy 10 pounds of crystals from a seed supply house for $32.

Note that I did purchase the blue crystals.

And then I found that well heres a twist..
Zinc sulfate from Greenway Biotech Contains 35.5% zinc and 16.5% sulfur

3 pounds on EBAY costs $13
http://www.ebay.com/itm/192046636849

So then I have to ask if ALL the zinc sulfate sold in garden centers and
hardware stores
contains SULFUR.... and IS toxic.

So I am sort of stumped here.
Can I build this battery using the hardware store zinc sulfate ...mixed with what...
water? diluted sulfuric acid? to make the liquid in the battery article refered to as sulfate of zinc solution?
and then
for the copper sulfate solution...
is that a mixture of water and the blue crystals?
So what I am trying to figure out is WHAT precisely I should be using as SULFATE of ZINC
and if using these chemicals poses an explosive mixture hazard risk.

And then... to really tip the scales of DONT TOUCH THAT
it says :
Tis well to amalgamate the zinc.

well... some more research... I added to below the article that explains why
the battery will work better with amalgamated zinc
BUT
the instructions say dip and wipe the zinc in mercury.

What happens if I leave out the mercury step?
Does the zinc corrode faster? Does the battery fail real fast? How fast?
or does it corrode and fail over time... time enough to demonstrate it does work as a battery for a while.

So which chemistry forum does this kind of question fit into?

[Borek]

Sorry from throwing you post here and there, it was moved to the Physical Chemistry by mistake.

So then I have to ask if ALL the zinc sulfate sold in garden centers and
hardware stores
contains SULFUR.... and IS toxic.

A molecule of zinc sulfate is ZnSO₄ - it contains one atom of zinc, one atom of sulfur and four atoms of oxygen, no matter what the source is. If you take atoms masses into account you will find it contains 19.86% of sulfur and 40.50% of zinc. However, that's for a pure zinc sulfate, the one sold contains impurities (or is just slightly wet) which makes these percentages (in a mixture, not in a compound!) a bit lower.

Note that copper sulfate contains sulfur as well.

And finally, toxicity of a compound has generally nothing to do with the toxicity of its components, especially in their elementary form. This can be a bit more complicated though, as you will see below.

So I am sort of stumped here.
Can I build this battery using the hardware store zinc sulfate ...mixed with what...
water? diluted sulfuric acid? to make the liquid in the battery article refered to as sulfate of zinc solution?
and then
for the copper sulfate solution...
is that a mixture of water and the blue crystals?
So what I am trying to figure out is WHAT precisely I should be using as SULFATE of ZINC
and if using these chemicals poses an explosive mixture hazard risk.

Looking at the chemistry of such battery I would start with just copper sulfate solution and a zinc plate, these are what really reacts here. Acidifying solutions is a good idea, but not absolutely necessary, zinc sulfate will lower the resistivity of the solution but it will also lower the voltage. Kitchen salt should work as well here.

Tis well to amalgamate the zinc.

Forget about using mercury and amalgams. Mercury happens to be toxic in almost every form and you won't be able to buy it.

Please remember about safety - for the chemicals here (assuming you won't be using battery acid, which is highly concentrated) gloves, glasses and a reasonable ventilation (which are always a good idea when working with chemicals) are perfectly enough.

[KB3BYT]

Thanks for the reply.
+++++++++++++++++++++++++++++++++++++++++++++++++++
RE:Looking at the chemistry of such battery I would start with just copper sulfate solution and a zinc plate, these are what really reacts here. Acidifying solutions is a good idea, but not absolutely necessary...
++++++++++++++++++++++++++++++++++++++++++++++++++
There is a shot glass of copper sulfate with the dowel and copper sheet
wicking the copper sulfate with burlap
and
there is another layer of burlap wicking the zinc sulfate.
So are you saying leave out the zinc sulfate?

[Borek]

So are you saying leave out the zinc sulfate?

What happens in the battery is that the copper is being deposited from the solution, the metallic zinc is being dissolved and some kind of its salt is produced. Wick serves as so called salt bridge, through which sulfate ions can flow from one cell to another. So in the end you will have zinc sulfate in the zinc cell regardless of whether it was put there at the beginning or not.

As I said earlier, you need to add some salt to the solution to make sure it won't have too high resistivity. Zinc sulfate will do, but many other salts will work, including those much easier to buy.

[KB3BYT]

The zinc sulfate and the copper sulfate is definitely easy to buy.
What I want to know is if the modern day zinc sulfate sold in hardware stores is OK to use in this battery as described by the author.
My confusion arises by the fact that zinc sulfate in the PHARMACY is a vitamin
suppliment and zinc sulfate in the hardware store is plant food... is toxic..and is labeled that it contains sulfur.

[AWK]

https://www.sciencecompany.com/Learn-Chemical-Grade-Definitions-from-Highest-to-Lowest-Purity..aspx

Zinc sulphate in the pharmacy shop should be U.S.P. purity (but in tablets it may be accompanied by other substances like sugar, starch and so on).
Four your battery technical grade is sufficient (and much cheaper).

[Borek]

What I want to know is if the modern day zinc sulfate sold in hardware stores is OK to use in this battery as described by the author.

Most likely yes. It can contain impurities which will interfere though.

My confusion arises by the fact that zinc sulfate in the PHARMACY is a vitamin suppliment and zinc sulfate in the hardware store is plant food... is toxic.. and is labeled that it contains sulfur.

And it is exactly the same compound. It is a dose that makes a poison, we need small quantities of Zn, but too much is dangerous for the health.

I have explained the part about sulfur earlier.

[KB3BYT]

THANK YOU