# Does copper(III) nitrate exist?

I was balancing this reaction when I found an unusual compound had been formed. $$\ce{Cu(s) + HNO_3(aq)-> Cu^{3+}(aq) + NO(g)}$$

My attempt:-

Balancing oxidation number:- $$\ce{Cu -> Cu^{3+} +3e^-}$$ $$\ce{3e^- + NO_3- -> NO}$$ Balancing hydrogen and oxygen atoms:- $$\ce{3e^- + 4H^+ + NO_3- -> NO + 2H_2O}$$ Adding $\ce{3NO3-}$ on both sides to form compounds :- $$\ce{3e^- + 4H^+ + 4NO_3- -> NO + 2H_2O + 3NO_3-}$$ Adding both half reactions $$\ce{Cu + 4H^+ + 4NO_3- -> NO + 2H_2O + Cu^{3+} + 3NO_3-}$$ $$\ce{Cu + 4HNO_3 -> NO + 2H_2O + Cu(NO_3)3}$$

So does this compound $\ce{Cu(NO3)3}$ actually exist? or have I done a mistake.

• Could you clarify where the first equation came from. I'm guessing that you were trying to determine what the products would be for copper reacting with nitric acid and you developed the equation rather than trying to "balance it". – MaxW Nov 4 '15 at 3:30
• I had a test yesterday and it was in the paper. – Rahul Gupta Nov 4 '15 at 3:41
• Did some digging with Google. Evidently some Cu+3 compounds exist as an anion complex where copper has organic ligands. pubs.acs.org/doi/abs/10.1021/ja00244a020 The equation does balance. However $\ce{Cu(NO3)3}$ does not exist. – MaxW Nov 4 '15 at 3:59
• Copper (iii) salts need a very basic anion such as fluoride to form , for this reason it mostly exists as an oxide or fluoride or something like that. I'm not sure whether the nitric acid would form the copper (iii) nitrate salt. – Technetium Nov 4 '15 at 4:06
• Inorganic chemists have cooked up some weird chemicals. I'd be curious as to how copper (iii) nitrate could be prepared. – MaxW Nov 4 '15 at 4:51