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What is the colour of elemental Ag? I have doubt whether it is black or silver in colour.

  • In Tollens' test, we get a silvery precipitate of elemental silver - hence silver in colour.

  • I have read somewhere and also in the following links as a reference that it was not mere speculation

http://books.google.co.in/books?id=AFY2gKwh4AsC&pg=PA553&lpg=PA553&dq=elemental+silver+precipitate&source=bl&ots=nzfsQcBAm6&sig=jTCQk7-k0HzAByI25ESI6OSclJs&hl=en&sa=X&ei=S1d7U6aXIY-OuASHp4HIDQ&redir_esc=y#v=onepage&q=elemental%20silver%20precipitate&f=false

(towards the end) and

http://books.google.co.in/books?id=cZL_-hyw98sC&pg=PA675&lpg=PA675&dq=elemental+silver+precipitate&source=bl&ots=DDhdhikKhU&sig=zIq-qQM7VI4i5enohZVi3oIagHw&hl=en&sa=X&ei=S1d7U6aXIY-OuASHp4HIDQ&redir_esc=y#v=onepage&q=elemental%20silver%20precipitate&f=false

Please confirm this. Thanks in advance.

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  • $\begingroup$ @LievenB Thanks was kind of suspecting this 'colour' definition issue.... $\endgroup$ – Kaustubh May 20 '14 at 16:19
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Silver:

enter image description here

Silver sulfide precipitate is black. You are pobably confusing a precipitate in a test for silver, with actual silver. The precipitate in a test will be a compound of silver, such as silver sulphide which is black.

Nanophase metal particles are optically different from bulk in many cases, and can be black, but this doesn't seem to be what the question is referring to.

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  • $\begingroup$ I knew that silver sulphide is black and just another article I found- questions.sci-toys.com/node/130 (3rd paragraph) (mainly metallic Ag also some Ag2O produced) staining by AgNO3, please verify. Anyway thanks... $\endgroup$ – Kaustubh May 20 '14 at 16:13
  • $\begingroup$ I don't see that statement in the reference, instead it is saying silver chloride is responsible for black stains on skin. $\endgroup$ – DavePhD May 20 '14 at 16:18
  • $\begingroup$ just after the mention of silver chloride -- "Silver nitrate will react with the skin and the salt on the skin to form silver chloride, which will them break down in strong light to form tiny particles of silver. These silver particles stay stuck in the skin, and look black". $\endgroup$ – Kaustubh May 21 '14 at 15:36
  • $\begingroup$ ok, I see now. The only reason I know of for an elemental metal to be black is if the particles are on the nanometer scale. $\endgroup$ – DavePhD May 21 '14 at 15:51
  • $\begingroup$ What about the nanometer scale, could you please elaborate, I don't even have a hint of any relation of its colour to any 'nanometer scale', anyway I have a feeling towards the next answer by LievenB, suspected that only but asked here just to confirm, thanks... $\endgroup$ – Kaustubh May 21 '14 at 15:55
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(this is just to illustrate with an image, even though the answer was already formulated by DavePhD )

It depends on what you define as colour - a silver bar will be metallic-silver, however silver powder may seem gray (or even black in water) (see image: http://www.nbchangjing.com/upload/2009031714521679.jpg )

I recently performed this silver-compound reaction : $\ce{Zn + 2AgNO3 -> Zn(NO3)2 + 2Ag}$ After a minute you could clearly see silver 'growing' from the zinc wire that I added to the silver nitrate solution. The silver was powdery black, however when I 'flattened' the silver powder, I had a silver-metallic surface.

I even found an image of a similar reaction involving copper wire :

enter image description here

You clearly see that there is a grayish-black silver powder forming on the wire, yet this doesn't have the same colour as a silver coin, for example.

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