Chemistry of Copper...

Question

What happens when a 0.02-grams copper metal is reacted with at most 10 drops of concentrated Nitric acid (HNO3)? There is a gas that evolves from the reaction. Can anyone tell me what that gas is and the other products of this chemical reaction? Also, what happens when the product of the reaction mentioned is subjected to 10 drops of water?

Answer 1

Concentrated nitric acid oxidizes the copper, turning the solution blue due to formation of Cu^2+ ions, and brown NO2 gas is formed.  The chemical equation is:

Cu (s) + 4HNO3 (aq) --> Cu(NO3)2 (aq) + 2NO2 (g) + 2H2O (l)

When you add more water, nothing more will happen.