Burning Silver-How is it Done?

[HamChem]

A Tech Ed. Teacher at the school I teach at thought he came across some "silver soldering" material. He said it used to be used years ago, now has been replaced by the stereotypical magnesium compound. He asked me a way to determine if it is silver or a silver compound. Any ideas on how to determine this? I suggested a simple flame test. Any other suggestions? (It is shaped like a rod.) Please respond.

 

Thanks

[freeztar]

I found this with a quick search.

 

WikiAnswers - How can you determine if metal is silver

[alexander]

"silver soldering" material

in silver solder, silver makes up for at most 3-5%... at which point, without some very special tools, you will not be able to determine silver content...

 

if it is indeed something that is nearly pure silver, then nitric acid is a bullet proof test.

 

other then that, silver has the highest thermal and electrical conductivity of any metal, and can not be magnetized.

[alexander]

found this too:

Silver Testing

[modest]

A Tech Ed. Teacher at the school I teach at thought he came across some "silver soldering" material... He asked me a way to determine if it is silver or a silver compound.

 

I believe all silver solder rods contain silver... otherwise they wouldn't be silver solder.

 

He said it used to be used years ago, now has been replaced by the stereotypical magnesium compound.

 

I also don't think there are any silver solders with magnesium, maybe he meant manganese?

Here is a table (sorry it's google book, that's all I could find)

 

He asked me a way to determine if it is silver or a silver compound. Any ideas on how to determine this? I suggested a simple flame test.

 

I don't think a flame test works with silver. The usual method is nitric acid which Freeztar links:

 

I found this with a quick search.

 

WikiAnswers - How can you determine if metal is silver

 

But, as I recall doing this... you add a drop of saltwater after you add the drop of nitric acid which the link doesn't say. The milky white precipitate should be silver chloride which shows up if you mix silver nitrate and salt water... so I think the salt water is most necessary - I'm not sure why this link leaves that out.

 

~modest

[alexander]

Modest, link i provided refers to this for a testing solution:

"A testing solution of potassium bichromate, 1 ounce, pure nitric acid, 6 ounces, and water, 2 ounces" :)

[modest]

Modest, link i provided refers to this for a testing solution:

"A testing solution of potassium bichromate, 1 ounce, pure nitric acid, 6 ounces, and water, 2 ounces" :hyper:

 

Very good. And it looks like that method will give an idea of the amount of silver. Your link also says:

 

A simpler method is as follows: Rub the piece to be tested on the touchstone and moisten the mark with nitric acid, whereupon it disappears. Add a little hydrochloric acid with a glass rod. If a white turbidness (silver chloride) appears which does not vanish upon addition of water, or, in case of faint silvering or an alloy poor in silver, a weak opalescence, the presence of silver is, certain. Even alloys containing very little silver give this reaction quite distinctly.

 

Which I think is a better method for determining if silver is present in any quantity. A person could also substitute salt water where this quote says hydrochloric acid. Freezy's link omits the HCl or NaCl which I'm quite sure wouldn't work.

 

~modest

[alexander]

ooh, now to just get some nitric and hydrochloric acids, and i'm golden... silver i mean

 

but having these, opens up a whole slew of fun exothermic reactions that one is capable of acheiving... that are much more fun :hyper: