Sciencemadness Discussion Board - Diammine Silver Complexes

Diammine Silver Complexes

ScienceHideout - 11-10-2014 at 05:38

So, I prepared Tollen's reagent- but not in the typical way. Instead of adding sodium hydroxide to get the oxide and dissolve it in NH3, I just left out the step and added, dripwise, ammonium hydroxide to silver nitrate until it turned brown, then clear.

What I need to figure out- is the complex I made diammine silver nitrate, or diammine silver hydroxide? Is there a chemical test for this?

blogfast25 - 11-10-2014 at 06:08

Quote: Originally posted by ScienceHideout

What I need to figure out- is the complex I made diammine silver nitrate, or diammine silver hydroxide? Is there a chemical test for this?

Firstly, you understand that such solutions are inherently unstable, especially concentrated ones?

I refer (among others) to an accident that occurred in my lab using such solutions:

http://www.sciencemadness.org/talk/viewthread.php?tid=32782#...

"I made diammine silver nitrate, or diammine silver hydroxide?"

You've made neither and both. The silver diammine complex, Ag(NH3

2+(aq) is a solvated complex ion. In your solution you have also nitrate and hydroxide ions but that makes it neither diammine silver nitrate, nor diammine silver hydroxide as everything is in solution. It's just a soup of these ions in water.

Whatever you do, do not try and evaporate your solution to isolate either the hydroxide of nitrate because it WILL detonate, because of explosive silver nitride (A3N) formation.

DON'T keep your preparation for more than 24 h. Also dispose of spent solutions (used for silver mirroring) within 24 h.

Be careful.

[Edited on 11-10-2014 by blogfast25]

ScienceHideout - 11-10-2014 at 07:45

Blogfast,

Thanks so much for response. Basically, the reason why asked is because I am making silver colloids, and I couldn't figure out the stoiciometry for the life of me after doing a titration. It just slipped my mind, that the nitrate and hydroxide are spectator ions. It all makes sense now, my hero! Thanks So much, and thanks for your safety concerns as well. I have been aware of the fulmination issues, and I always reduce my leftovers before I exit the lab. Thank you, thank you thank you. ..

Dean

ScienceHideout - 11-10-2014 at 08:25

Oops, I am using this website on my phone and some reason it posted twice. .. sorry about this. Moderators, you may delete this message if you so desire.

[Edited on 11-10-2014 by ScienceHideout]