Kagutsuchi
Hazard to Self
Posts: 51
Registered: 21-6-2015
Location: Hungary
Member Is Offline
Mood: Happy
|
|
Identifying reaction product
I've dissolved some copper in nitric acid but there was a little nitric acid left in the solution. I added some ammonia to form a complex with the
Cu2+ ions, but accidently I added some Na2CO3. Some light blue solid material formed in the solution. Does anyone have an idea what could it be?
|
|
|
Loptr
International Hazard
Posts: 1347
Registered: 20-5-2014
Location: USA
Member Is Offline
Mood: Grateful
|
|
The precipitate is likely basic copper carbonate, CuCO3.
Cu(NO3)2 + Na2CO3 -> CuCO3 + 2 NaNO3
It would also help if you provided the amounts of reactants used.
[Edited on 23-6-2015 by Loptr]
|
|
|
diggafromdover
Hazard to Self
Posts: 84
Registered: 24-2-2015
Location: New Hampshire
Member Is Offline
Mood: Inconherent
|
|
Copper Carbonate? Copper Carbonate is not water soluble and as such would precipitated. It's a one way reaction.
|
|
|
Kagutsuchi
Hazard to Self
Posts: 51
Registered: 21-6-2015
Location: Hungary
Member Is Offline
Mood: Happy
|
|
I used about 5-6 grams of Cu(NO3)2, 20 ml of circa 60% nitric acid and 15 grams of Na2CO3.
|
|
|
MrHomeScientist
International Hazard
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
By some rough stoichiometry calculations, 15g of carbonate is just about enough to neutralize 20mL of your acid. That plus the ammonia you added (you
didn't specify how much) means your solution is almost certainly pH >= 7, allowing some copper carbonate to fall out. It's about the only
possibility for the blue solid, really.
Also, basic copper carbonate is Cu<sub>2</sub>(OH)<sub>2</sub>CO<sub>3</sub>.
CuCO<sub>3</sub> by itself doesn't really exist (or at least, it's extremely hard to make).
|
|
|
Loptr
International Hazard
Posts: 1347
Registered: 20-5-2014
Location: USA
Member Is Offline
Mood: Grateful
|
|
Ah, that's right. CuCO3 reacts with water to form basic copper carbonate.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Hmmm.... in a sense:
2 Cu<sup>+</sup>(aq) + 2 CO<sub>3</sub><sup>2-</sup> (aq) + H<sub>2</sub>O(l) === >
Cu<sub>2</sub>(OH)<sub>2</sub>CO<sub>3</sub>(s) + CO<sub>2</sub>(g)
Copper basic carbonate is kind of a double salt: CuCO3.Cu(OH)2
[Edited on 23-6-2015 by blogfast25]
|
|
|
Kagutsuchi
Hazard to Self
Posts: 51
Registered: 21-6-2015
Location: Hungary
Member Is Offline
Mood: Happy
|
|
Thanks guys, it really seems that way. The ammonia was about 20 ml 20% ammonia but I think you were right about the case. Later today I'll do some
analytical testing but I did not have time for that yesterday 
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
