How do you classify this reaction? #8HNO_3 (aq) + 3 Cu (s) + O_2 (g) -> 3Cu(NO_3)_2 (aq) + 4H_2O + 2NO_2 (g)#

1 Answer
Aug 15, 2017

Answer:

This is CLEARLY a redox process, which we represent by invoking electrons as virtual particles........I do not think dioxygen is a reasonable reactant.

Explanation:

Copper is oxidized up to cupric ion, #Cu^(2+)#:

#Cu(s) rarr Cu^(2+) + 2e^(-)# #(i)#

Nitrate ion #N(V)# is REDUCED to #NO_2(g)#, #N(IV)#:

#NO_3^(-) +2H^(+) +e ^(-) rarr NO_2 +H_2O# #(ii)#

We take #(i) + 2xx(ii)# to give......

#Cu(s) + 2NO_3^(-) +4H^(+) +cancel(2e ^(-)) rarr Cu^(2+) + cancel(2e^(-))+2NO_2 +2H_2O#

And cancel out the common reagents......

#Cu + 2NO_3^(-) +4H^(+) rarr Cu^(2+) +2NO_2 +2H_2O#