Preparation of Copper(I) Chloride Reactions: 1) Cu(S) + 4HNO 3 (aq) -> Cu(NO 3 )
ID: 946698 • Letter: P
Question
Preparation of Copper(I) Chloride
Reactions:
1) Cu(S) + 4HNO3(aq) -> Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)
2) 2HNO3(aq) + Na2CO3(s) -> H2O(l) + CO2(g) + 2NaNO3(aq)
3)Cu(NO3)2(aq) + Na2CO3(s) -> CuCO3(s) + 2NANO3(aq)
4)CuCO3(s) + 2HCL(aq) -> CuCl2(aq) + H2O(l) + CO2(g)
5)CuCl2(aq) + Cu(s) -> 2CuCl(s)
Report:
Weight of Copper: 1.004g
Volume of Added Nitric Acid: 4.9mL
Total weight of added Sodium Carbonate: 3.841g
Weight of watch glass and filter paper: 51.740g
Weight of watch glass, filter paper, and CuCl Precipitate: 53.513g
Experimental Yield of CuCl: 1.775g
Theoretical Yield of CuCl: 3.55g
Percent Yield of CuCl: 50%
Could we use HCl to dissolve the copper metal instead of nitric acid in the first reaction? Please explain.
Explanation / Answer
NO.
When you are using Hydrochloric Acid (aka: HCl), it will "attack" nearly anything above hydrogen, including, Lead, Aluminum, Magnesium, Tin, Zinc, etc. (Lead is a bit of a challenge for HCl because Lead Chloride is insoluble, and can form a protective coat that stops the reaction from occurring. It does actually react on the surface and if you add some heat to the reaction, it can push it even further.) But, as Copper is below Hydrogen, it is not attacked by HCl...
With Nitric Acid (aka: HNO3), in dilute form, the reaction is the same as with HCl... However, if you are using concentrated HNO3, the nitrate portion of the acid IS able to attack the Copper... This, because the nitrate is a powerful oxidizing agent when in high concentration. The nitrate portion is reduced to NO2 gas and the metal is oxidized. This reaction allows concentrated nitric acid to also attack metals that are "below" hydrogen (to some extent). Mercury, copper, and silver are all readily attacked by this reaction...