Sciencemadness Discussion Board - silver nitrate

silver nitrate

Lithium - 9-3-2012 at 20:55

hello

i want to sell silver nitrate, because i can buy and make all the chemicals relatively cheaply, and make a profit on it.

my only concern is if people will actually want to buy from me, and not a chem supplier giant. it will only be on ebay or amazon.

another problem is the quantity of calcium nitrate and sulfuric acid i would buy, would it raise some eyebrows?

Li

Hexavalent - 9-3-2012 at 23:54

I know some people might be uncomfortable buying from a comparatively new member . . .consider using PayPal, and it will make people a lot more at ease.

To sell the stuff, you will need to make sure that it is quite pure, to the grade that you sell it as or above. Look into recrystallizations or other techniques.

Personally, my chemistry teacher has promised me a few grams of silver metal . . .you know the copper wire in AgNO3 experiment? He's done that 5 times recently, he normally saves the precipitated silver, shows it to his class and then chucks it . . .this time, I'll be coming in with a labeled vial on Monday

Lithium - 10-3-2012 at 00:14

yes, i know how to recrystalize

i would sell it on ebay, which i think has paypal as a payment selection.

is it legal in aus to buy lots of nitrates and H2SO4, i suppose it should be fine if i buy silver bullion with it

Li

Endimion17 - 10-3-2012 at 04:22

Quote: Originally posted by Hexavalent

I know some people might be uncomfortable buying from a comparatively new member . . .consider using PayPal, and it will make people a lot more at ease.

To sell the stuff, you will need to make sure that it is quite pure, to the grade that you sell it as or above. Look into recrystallizations or other techniques.

Personally, my chemistry teacher has promised me a few grams of silver metal . . .you know the copper wire in AgNO3 experiment? He's done that 5 times recently, he normally saves the precipitated silver, shows it to his class and then chucks it . . .this time, I'll be coming in with a labeled vial on Monday

He THROWS AWAY silver?!

barley81 - 10-3-2012 at 06:06

Sadly, most high school chem teachers do. The other day, the chemistry club at my school tried to make silver mirrors (one person dropped their test tube and we had to abort). I tried to save the silver but the teacher wouldn't let me. She threw it out. Aargh.

That teacher is too much. It's her second year at my school, and she teaches both the advanced (senior) and the regular chemistry courses. She asked me why sugar was a reducing agent during an experiment

Endimion17 - 10-3-2012 at 06:31

Even the lab manuals dictate that precious metals should be collected and appropriately precipitated.
Throwing the silver away is one of the most stupid things to do, and it costs the school a lot of money. Silver nitrate is expensive, and it's one of the easiest things to recycle.

I understand they throw silver mirrored tubes away (the amount inside is way too small), but precipitated silver tree from a copper wire contains a lot more. Throwing that away is just ridiculous. I'd tell the teacher that he/she is making unneccessary costs to the school budget.

barley81 - 10-3-2012 at 06:49

No, it wasn't the tubes she threw away, but the silvering solution. There was a fair amount of silver oxide precipitate after dilution.

neptunium - 10-3-2012 at 06:58

dont sale your stuff on ebay ! ebay is great for a buyer but your product will end up on the business and industrial section and you'll be taxed 9% on every sale!!!!!!!!

I dont know how big time seller do it on there but every time i had some to sale i got f."@/d hard!!

Lithium - 10-3-2012 at 14:11

well, i am giving up on the idea of selling silver nitrate, but i still want to make some

i will probably think otherwise when it is the school holidays

can you react silver with liquid sulfur and dissolve that in HNO3 ( i have a use for H2S )

i have found about eight australian sixpence from 1941, which are apparently sterling silver. my grandma also broke two of her silver rings. all up i have about 35g silver. i have saved up 5 old phones, and an iphone that doesn't work, how do i refine them?

Li

barley81 - 10-3-2012 at 14:18

Don't bother with the sulfur and silver. Just dissolve the silver in the nitric acid to minimize contamination. To make hydrogen sulfide, just heat some paraffin wax and sulfur together. You get carbon and H2S.

There are a few threads around here about refining sterling silver. IIRC, you can fuse the silver nitrate and decompose the copper nitrate into copper oxide, and filter that off once you dissolve it in water.

BILLBUILDS - 25-8-2017 at 13:52

whats the method of making AgNO3? i have a few kg's of family silver which has no use anymore (people that it was important to are all dead)

ninhydric1 - 25-8-2017 at 14:10

Silver and nitric acid. And please UTFSE. There are too many threads on AgNO3 synthesis.

clearly_not_atara - 25-8-2017 at 19:15

IMO better to make the methanesulfonate which can be made with MeSO3H/H2O2 and which generates no toxic gases upon decomposition. Ethanesulfonate may have comparable solubility.

https://www.alfa.com/en/catalog/018641/

Melgar - 25-8-2017 at 21:08

First off, silver is only like $1/gram. That's not super cheap, true, but a 99.9% silver dollar typically costs like $30. It's not really that expensive.

If you want to sell a chemical on eBay that you can make quite a lot on, go for PdCl2. It's a precious metal salt, so nobody expects it to be cheap, however you can sell it for more than the palladium spot price, even though it's 60% chlorine by mass. To make it, just drop $800 or so on an ounce of palladium (anything less rarely gets you close to the spot price), dissolve in aqua regia, then evaporate.

Anyone know of a decent way to refine silver chloride? Everyone seems to think it's a pain in the ass, but couldn't you just heat it red hot with sugar or something?

unionised - 26-8-2017 at 05:27

AgCl will give silver if you melt it with Na2CO3

clearly_not_atara - 26-8-2017 at 13:02

Melgar - PdCl2 is a crucial component of a certain reaction used in the synthesis of a certain compound with a very high profit margin. As such it may be important to have one's legal ducks in a row before selling PdCl2 to strangers online. I don't know why the demand exists but I know people (blogfast) have gotten popped for selling less interesting stuff to less interesting people.

I'm pretty sure AgCl dissolves in concentrated hydrochloric acid; that solution can probably be easily reduced.

[Edited on 26-8-2017 by clearly_not_atara]

Melgar - 26-8-2017 at 20:34

Quote: Originally posted by clearly_not_atara

Melgar - PdCl2 is a crucial component of a certain reaction used in the synthesis of a certain compound with a very high profit margin. As such it may be important to have one's legal ducks in a row before selling PdCl2 to strangers online. I don't know why the demand exists but I know people (blogfast) have gotten popped for selling less interesting stuff to less interesting people.

Wacker oxidation of safrole? Yeah, I know, but as long as you're not advertising that as its purpose, it's not a controlled or restricted chemical in any way. Maybe slightly suspicious, but it's also the most commonly used palladium salt for every other purpose that you'd have. However, the demand on eBay is certainly fueled by the demand for the reductively aminated product of this reaction, I'm sure we can agree.

AJKOER - 7-10-2017 at 09:28

I read (and attempted) in some old texts that AgClO3 can be prepared from the action of chlorine (aq) on a say silver oxide (or silver carbonate). Soon after preparation, add Ag2O to stabilize the AgClO3 product.

After you have perfected that path along with the recycling of AgCl to silver, add cheap available KNO3:

AgClO3 + KNO3 = AgNO3 + KClO3

and you have two good salts.
--------------------------------------

Sources: To quote from "A comprehensive treatise on inorganic and theoretical chemistry", Volume 2, by Joseph William Mellor, page 271:

"L. N. Vauquelin found that when chlorine acts on silver oxide diffused in water, a mixture of silver chloride and chlorate is formed, and it was accordingly supposed that these same products are obtained when chlorine acts on the salts of silver. The products observed by L. N. Vauquelin were shown by A. J. Balard to be end products, being preceded by the formation of silver hypochlorite. According to A. J. Balard, finely divided silver immediately decomposes hypochlorous acid with the evolution of oxygen, and the formation of silver chloride. Again, if an alkali hypochlorite be treated with silver nitrate, or if silver oxide, Ag20, suspended in water, be treated with chlorine, much heat is developed and silver chloride and silver peroxide are precipitated while a liquid with bleaching properties is formed. The liquid is very unstable, and decomposes in a few minutes with the separation of silver chloride and the formation of a soln. of silver chlorate which does not bleach. If an excess of chlorine be employed, all the silver is precipitated and a soln. of hypochlorous and chloric acids remains. If an alkali hydroxide be added to the bleaching liquid, oxygen is evolved, and a mixture of silver chloride and peroxide is precipitated. Similar results are obtained if an aq. soln. of silver chlorate, nitrate, or acetate be employed except that the corresponding acid is liberated. J. S. Stas has •shown that probably no chloric acid or silver chlorate is formed in the primary reaction:

Ag20+2Cl2+H20=2AgCl+2HCl0

If the silver oxide or carbonate be in excess, the silver oxide gradually forms silver hypochlorite,

2HOCl + Ag20 =2AgOCl+H20

which is readily soluble, and the soln. is stable so long as it is shaken with the excess of silver oxide present. This salt is partially decomposed on standing in darkness, and completely decomposed at 60° into silver chloride and chlorate:

3AgOCl=2AgCl+AgCl03

and the latter remains in soln. in the alkaline liquid. J. S. Stas found no signs of the formation of perchloric acid. F. Raschig prepared silver hypochlorite by the action of alkaline sodium hypochlorite on silver nitrate, and also by adding a soln. of silver nitrate to sodium azide, NaN3, or to a soln. of chloroazide in sodium hydroxide."

Link: https://books.google.com/books?pg=PA271&lpg=PA271&dq...

So the formation of Silver Chlorate is apparently not slow and one can actually visibly observe the formation of the AgCl. I suspect that AgClO3 should be quickly be employed in a reaction, or dried per the directions, as the aqueous solution is most likely not stable. In fact, Mellor (cited previously), page 340, notes that AgClO3 decomposes into AgCl and O2 in the presence of HCl, HNO3 and even Acetic acid. Chlorine also reacts forming AgCl, HClO3 and O2.

Also per another source "The principles of chemistry", Volume 2, by Dmitrïi Ivanovich Mendelieev, the bottom of page 403, to quote:

"This is how he describes the phenomenon which then takes place: if silver oxide or carbonate be suspended in water, and an excess of water saturated with chlorine be added, then all the silver is converted into chloride, just as is the case with oxide or carbonate of mercury, and the water then contains, besides the excess of chlorine, only pure hypochlorous acid without the least trace of chloric or chlorous acid. If a stream of chlorine be passed into water containing an excess of silver oxide or silver carbonate, while the liquid is continually shaken, then the reaction is the same as the preceding; silver chloride and hypochlorous acid are formed. But this acid does not long remain in a free state; it gradually acts on the silver oxide and gives silver hypochlorite. If, after some time, the current of chlorine is stopped but the shaking is continued, then the liquid loses its characteristic odour of hypochlorous acid, while preserving its energetic decolorising property, because the silver hypochlorite which is formed is easily soluble in water. In the presence of an excess of silver oxide this salt can be kept for several days without decomposition, but it is exceedingly unstable when there is not an excess of silver oxide or carbonate present. So long as the solution of silver hypochlorite is shaken up with the silver oxide, it preserves its transparency and bleaching property, but directly it is allowed to stand, and the silver oxide settles, it becomes rapidly cloudy and deposits large flakes of silver chloride, so that the black silver oxide which hud settled becomes covered with the white precipitate. The liquid then loses its bleaching properties, and contains silver chlorato iu solution,...."

And from the bottom of page 404:

" In this manner the reactions whiih are consecutively accomplished may be expressed by the equations:

6Cl2 + 3Ag2O + 3H2O = 6AgCl + 6HCl0; 6HCl0 + 8Ag20 = 3 H20 + 6AgCIO;
6AgClO = 4AgCl + 2AgCl03.

Hence, Slas gives the following method for the preparation of silver chlorate. A slow current of chlorine is caused to act on oxide of silver, suspended in water, which is put into a state of continuous movement. The shaking is continued after the supply of chlorine has been stopped, in order that the free hypochlorous acid should pass into silver hypochlorite, and the resultant solution of the hypochlorite is drawn off from the sediment of the excess of silver oxide. This solution decomposes spontaneously into silver chloride and chlorate. The pure silver chlorate, AgClO3, does not change under the action of light. The salt is made ready for further use by drying it in dry air at 150°. It is necessary during drying to prevent the access of any organic matter; this is done by filtering the air through cotton wool, and passing it over a layer of red-hot copper oxide."

Link: https://books.google.com/books?pg=PA403&lpg=PA403&dq...

So either the presence of free Chlorine in the bleach (which effectively lows the pH by forming HCl and also HOCl), or by the direct addition of a weak acid (like CO2 or vinegar) forming HOCl, which reacts directly with Ag2O or AgCO3 to create the highly unstable silver hypochlorite. Then, AgClO quickly disproportionates into AgCl and AgClO3 unless there is an excess of Ag2O or AgCO3 to promote the stability of the Silver hypochlorite.

I had added NaClO to Silver acetate dissolved in Acetic acid. The bleach and weak acid formed HOCl, which then reacted with Silver acetate to form a white precipitate of AgCl. The solution also bubbled for a few weeks (O2 from the decomposition of AgClO3). Not the recommended path as acetic acid will decompose AgClO3 on standing.

Note, only 1/3 of the Silver metal is converted into AgClO3, so , without recycling, this is an expensive route, but you may have some Silver literally laying around. However, the above action path with KNO3 does introduce another salt of interest into the product mix.

Ag2CO3 can be prepared, for example, by adding silver to a solution of vinegar, H2O2 and a touch of KNO3 (acting as an electrolyte for this electrochemical path). Jump start in a microwave. At completion, add Na2CO3 to create a Ag2CO3 precipitate which is isolated and washed.

[Edited on 7-10-2017 by AJKOER]

Lithium

Sulaiman - 7-10-2017 at 11:12

I hope that this is not too late, I just read this thread,

Based on very limited experience,
if you make silver nitrate from a 99.9% silver dollar, the remaining 0.1% (mainly copper I suspect)
is enough to make it less than ideal for photochemistry experiments, and long term storage.
I suggest a 99.99% Canadian Maple.
or
If you are confident of the purity of your nitric acid, use a 99.999% silver Canadian Maple for a really good product.
I am not confident of the impurity levels in my nitric acid so have not tried - speculation only.

EDIT: I guess that most members here, like me, would have difficulty assaying to 0.1%, and I don't know off-hand how I would even attempt a 0.01% assay.

[Edited on 7-10-2017 by Sulaiman]

unionised - 7-10-2017 at 11:39

Quote: Originally posted by Sulaiman

I hope that this is not too late, I just read this thread,

Based on very limited experience,
if you make silver nitrate from a 99.9% silver dollar, the remaining 0.1% (mainly copper I suspect)
is enough to make it less than ideal for photochemistry experiments, and long term storage.
I suggest a 99.99% Canadian Maple.
or
If you are confident of the purity of your nitric acid, use a 99.999% silver Canadian Maple for a really good product.
I am not confident of the impurity levels in my nitric acid so have not tried - speculation only.

EDIT: I guess that most members here, like me, would have difficulty assaying to 0.1%, and I don't know off-hand how I would even attempt a 0.01% assay.

[Edited on 7-10-2017 by Sulaiman]

At that level, you generally don't.
You measure all the credible impurities, for example, copper, sodium and iron, then calculate the purity of the silver salt as (100- the sum of all the otehr stuff).

Typically you only measure metals and then report the purity as something like ">99.99% metals basis".
So you can get stuff labelled as 99.99% pure but which contains 5% water.
:-(

Sulaiman - 8-10-2017 at 03:00

So for my silver nitrate that I made from a 99.9% silver American Eagle, which has a very faint blue/green tint,
how would I measure the (assume c0.1% copper) impurity content ?

Metacelsus - 8-10-2017 at 06:06

AES would be the "gold standard" so to speak, but I doubt you have the equipment for that.

clearly_not_atara - 8-10-2017 at 15:28

Why would copper be so problematic in silver nitrate? Sigma sells it at 99% purity so I'm not sure what all this 99.99% stuff is about.

If you want to be rid of copper, you can precipitate silver as the acetate, and then pyrolyse this to the oxide and redissolve in HNO3 or just dissolve AgOAc in HNO3 and boil away acetic acid (hopefully without catching fire). That's a lot of work though... and no it won't give you a copper assay (but practically all metal acetates except silver will remain dissolved).

To observe the presence of copper, maybe add some of the (not acidic) nitrate solution to an excess of iodide salt -- Ag+ will precipitate as AgI whereas Cu2+ will oxidize I- to I2 and precipitate as CuI. The resulting I2 should give an obvious brown coloration to the solution (as triiodide).

Fleaker - 11-10-2017 at 11:19

Quote: Originally posted by clearly_not_atara

Why would copper be so problematic in silver nitrate? Sigma sells it at 99% purity so I'm not sure what all this 99.99% stuff is about.

If you want to be rid of copper, you can precipitate silver as the acetate, and then pyrolyse this to the oxide and redissolve in HNO3 or just dissolve AgOAc in HNO3 and boil away acetic acid (hopefully without catching fire). That's a lot of work though... and no it won't give you a copper assay (but practically all metal acetates except silver will remain dissolved).

To observe the presence of copper, maybe add some of the (not acidic) nitrate solution to an excess of iodide salt -- Ag+ will precipitate as AgI whereas Cu2+ will oxidize I- to I2 and precipitate as CuI. The resulting I2 should give an obvious brown coloration to the solution (as triiodide).

Or if you want to skip all that, just melt the silver nitrate, hold for 30 min at just over its melting point, and then dissolve up the silver nitrate and filter the solution free of other oxides. Melting silver nitrate is still an effective way of purifying it. Sodium formate is another method, wherein the first (things like Pd and Pt that co-dissolves with silver) and last fractions (Cu/Ni dragdown) are discarded for recycling and the middle fraction is very high quality silver.

Analysis of silver can be done via Volhard's method. Used to do quite a few of those titrations by hand--I'd use XRF to analyze an unknown sample and get a ballpark Ag %, then add titrant gravimetrically and use a microburette to finish it off. The titrant I would use (0.05N KSCN) was standardized against 5N+ proof silver. Using this method, I could reliably tell 99.5% from 99.95%. With a potentiometric autotitrator, the method is off by about $60 on every 100,000 in silver at $20/tr oz Ag. I still consider it the best/cheapest method of silver analysis despite owning an ICP-OES.

In any event, silver nitrate is stupid cheap--at industrial scale, there's a negligible premium to be had, maybe $0.30/50 grams. The old Kodak plant, now Rochester Silver Works, is probably the largest producer in the world. A very impressive operation. Their silver nitrate of trade is 5N on a metals basis with less than 0.1% moisture.

[Edited on 11-10-2017 by Fleaker]

MrHomeScientist - 11-10-2017 at 13:29

That's a really interesting way to purify silver nitrate; I hadn't heard of that before. Wikipedia claims:
"Silver nitrate decomposes when heated:
2 AgNO3(l) → 2 Ag(s) + O2(g) + 2 NO2(g)
Qualitatively, decomposition is negligible below the melting point, but becomes appreciable around 250 °C and totally decompose at 440 °C."
citing http://aip.scitation.org/doi/10.1063/1.3253104 as its source.

So that means it's important to keep it right at the melting point, as you said. Neat!

Fleaker - 12-10-2017 at 10:23

It is neat! often times it looks like black melt if really crude.

Let's just say I've done a few tons of silver!!