# How can I make AgNO3 more basic? [closed]

Is there anything that I can add to the AgNO3 solution that will make it more basic without forming a precipitate such as reacting with OH or HCl? Please be more specific and give an example.

• You are requesting to be more specific but could you explain more of this context, why do you want to increase the pH of the silver salt? What is the experimental requirement? – M. Farooq Apr 8 '20 at 15:45
• Because I am trying to then react to the solution of AgNO3 with NaCl to check if a more basic solution could affect the amount of precipitate formed because there will be a change in activation energy. I also used HNO3 solution to make the solution of AgNO3 more acidic and it worked so I wanted to see if there will be a difference with a basic solution. Do you also think if I used complexation of ammonia, would that give us a strong base and would that work for my experiment? – General MO7 Apr 8 '20 at 16:59
• The reaction of AgNO3 with NaCl is $quantitative$ as long as the silver ions are in solution (as long as the pH is acidic ,say < 6). By definition, a basic solution implies the presence of -OH ions in water, so silver ions will react with base and NaCl (both). There is no way to circumvent this problem. There is no point in spending time on this problem. – M. Farooq Apr 8 '20 at 17:09
• Just one last question for your valuable comments. I want to do a catalyst in my experiment, so then I decided on doing acid-base catalysis and the problem is that I won't be able to do a base as a catalyst (would [Cu (NH3)4(H2O)2] 2+ work or does it also has OH ions?) so in conclusion, do you have any idea for any other way to add a catalyst or if not even a variable apart from temperature and concentration that would probably result in a higher amount of precipitate. I know these are a lot of questions to ask but I have an essay due very soon and you're comments are very useful. thanks!!! – General MO7 Apr 8 '20 at 18:22
• I still do not understand your research topic. What is the topic? Every alkaline solution in water has -OH ions. That is it. You cannot avoid them by any means. – M. Farooq Apr 8 '20 at 20:56

## 1 Answer

If you dissolve silver nitrate $$\ce{AgNO_3}$$in water, and add some NaOH solution to make it basic, it will destroy your substance, and produce a brown precipitate of silver oxide $$\ce{Ag_2O}$$ : $$\ce{2 AgNO_3 + 2 NaOH -> Ag_2O + 2 NaNO_3 + H_2O}$$

But instead of using a hydroxide like $$\ce{NaOH}$$, you may add some ammonia solution $$\ce{NH_3}$$. In this case you will produce some $$\ce{Ag_2O}$$ in the very beginning, but this dark precipitate will soon be dissolved by more ammonia, and a nearly colorless solution of diamminosilver(I) is obtained : $$\ce{2 Ag^+ + 2 NH_3 + H_2O -> Ag_2O + 2 NH_4^+}$$$$\ce{Ag_2O + 4 NH_3 + H_2O -> 2 [Ag(NH_3)_2]^+ + 2 OH^-}$$

• That is a bad idea to mix Ag+ with ammonia. – Poutnik Apr 8 '20 at 16:38
• Continuing Poutnik's comment, there is always a threat of forming silver nitride. Also for context, see: chemistry.stackexchange.com/questions/43441/…. – Nilay Ghosh Apr 8 '20 at 17:43
• @Poutnik and Nilay Ghosh. If you try to evaporate this solution containing diamminesilver ions, silver nitride may be formed, which is explosive. But if you don't evaporate, you can use this solution without danger to produce nice silver mirrors on glass, I have done it with all my students in the lab, without any difficulty. You just have to add some glucose and a drop of NaOH, then to heat at 40°C (not more). You obtain a nice silver mirror. That is the way all mirrors were prepared in the19th and in the beginning of the 20th century. Now they are made in condensing aluminium vapors. – Maurice Apr 8 '20 at 20:43
• I look at the formation of silver nitride closely. My take on a photoactivation path, change in NH3 concentration, fostering reverse reaction to Ag2O, activation by light to Ag/Ag2O, a powerful visible light photocatalyst, introduction of the .NH2 radical forming AgNH2, 2 AgNH2 --> Ag2NH + NH3 followed by AgNH2 + Ag2NH --> Ag3N + NH3. – AJKOER Apr 9 '20 at 0:52
• @Maurice I am well aware of the purpose of that solution. But OP did not express the purpose and these solutions are not safe to store. They are recommended to be sanitised by HCl. Ag3N is formed if ammonia concentration is about 1.5 M or above, At cca 0.75 M it is not reportedly formed. – Poutnik Apr 9 '20 at 2:10