Metallic copper does not react with hydrochloric acid, but is oxidized by nitric
ID: 523079 • Letter: M
Question
Metallic copper does not react with hydrochloric acid, but is oxidized by nitric acid since the nitrate ion functions as the oxidizing agent in acidic solutions. If NO and Cu^2+ are formed as products, and the reaction is carried out under standard conditions, E^0 for the reaction of copper metal with nitric acid will be: A) +0.44 V B) +0.62 V c) +0.78 V D) +0.96 V HNO_3 (aq) + H_2O (l) rightharpoonoverleftharpoon NO^-_3 (aq) + H_3O^+ (aq) Cu(s) + NO^-_3 (aq) rightharpoonoverleftharpoon NO(g) + Cu^2+ (aq)Explanation / Answer
NO 3 - (aq) + 4H + (aq) + 3e - NO(g) + 2H 2O(l) E0 = +0.96 reduction at cathode
Cu2+(aq) + 2e - Cu(s) E0 = +0.34 oxidation at anode
E0cell = E0(cathode) – E0(anode) =0.96 -0.34 = 0.62 V