ChemistryForever
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AgOH
Is there any way you can synthesize silver hydroxide ? If you mix AgNO3 with NaOH it will give just Ag2O. Or silver hydroxide does not exist ?
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CharlieA
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https://en.wikipedia.org/wiki/Silver_oxide#Preparation
Did you do any search for information? I think the above article should answer your question.
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Tsjerk
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Apparently Ag2O is a bit soluble in water and forms a silver hydroxide solution.
Ag2O + H2O <-----> 2Ag+ + 2 OH-
With a log Ksp of about -7.7, that would be about 0.2mM, so you can make a solution of it at least...
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CharlieA
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According to the Wikipedia reference in my post above, the Ksp for AgOH is 1.52E-8 mol/L. From this value I calculate the solubility of AgOH at 1.2E-4
M or about 150mg AgOH per liter. I wouldn't consider this substance even sparingly soluble in water. But this is just my interpretation, and as they
say "it's all relative."
P.S. For the newbies, 1.52E-8 is exponential notation and is a shorthand way to express the number 1.52 times 10 to the -8 power.
Edited by Charlie to remove the unintelligiblity of the original post. I'm typing from a laptop and I have the annoyin habit of touching the touchpad
while typing, and the &*&*&*& cursor jumps all over the place, so the text that I am typing winds up all over the place. Besides this
problem I also write run-over sentences.
Charlie
[Edited on 1-15-2019 by CharlieA]
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SelfInflicted
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The hydroxide AgOH exists only in solution; otherwise it spontaneously decomposes to the oxide.
According to https://en.m.wikipedia.org/wiki/Silver
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Tsjerk
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Quote: Originally posted by CharlieA  | According to the Wikipedia reference in my post above, the Ksp for AgOH is 1.52E-8 mol/L. From this value I calculate th1ess I wouldn't consider this
substance even sparingly soluble in water. But this is just my interpretation, and as they say "it's all relative."
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Maybe the wiki concentration is for alkaline solutions? Although silver mainly exists as AgO- in alkaline solution.
Here is an experimental article on the subject.
Attachment: johnston1933.pdf (956kB)
This file has been downloaded 474 times
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CharlieA
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@Tsjerk: thanks for the copy of that article (it's even older than me). I am enjoying reading it and puzzling it out.
Charlie
Edit: ...it's even older than I (am old)...
[Edited on 1-15-2019 by CharlieA]
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chemister2015
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Silver hydroxide can be obtained at -50 ° C by pouring out alcoholic solutions of silver nitrate and potassium hydroxide.
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AJKOER
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Interestingly, the limited solubility of Ag2O producing AgOH is not necessarily limiting!
In the following system:
Ag2O + H2O <---> 2 AgOH
2 AgOH + 2 Cl- --> 2 AgCl (s) + 2 OH-
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Net: Ag2O + H2O + 2 Cl- --> 2 AgCl (s) + 2 OH-
So adding KCl to a suspension of Ag2O in water can result in strong KOH (capable of attacking glass, as I discovered accidentally) as the formation of
the insoluble AgCl apparently drives the first equilibrium reaction to the right.
An extract of my prior comment:
Link: http://www.sciencemadness.org/talk/viewthread.php?tid=117891
[Edited on 5-2-2019 by AJKOER]
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Sulaiman
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would this reaction not occur ?
4AgCl + 4KOH «→» 4KCl + 4Ag + O2 + 2H2O
which would consume the KOH
CAUTION : Hobby Chemist, not Professional or even Amateur
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Tsjerk
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@ AJOEKER; Just read the abstract.
Attachment: willbanks1953.pdf (706kB)
This file has been downloaded 352 times
@ Sulaiman; not in water. The reaction you propose is driven to the right because of the precipitation of Ag2O. The product van be decomposed by heat,
but the equilibrium you wrote doesn't make sense as it implies silver making its way back to the chloride. As a total scheme of two reactions your
scheme is correct though.
[Edited on 5-2-2019 by Tsjerk]
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