Question

You are given the reaction Cu + HNO3 → Cu(NO3)2 + NO + H2O.

Half-reactions:
3Cu → 3Cu²⁺ + 6e
2N⁵⁺ + 6e⁻ → 2N²⁺
Complete the final balanced equation based on the half-reactions.

A) 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O
B) 2Cu + 6HNO3 → 2Cu(NO3)2 + N2O + 3H2O
C) 3Cu + 2HNO3 → 3Cu(NO3)2 + N2O + H2O
D) 2Cu + 4HNO3 → 2Cu(NO3)2 + 2NO + 2H2O

Answer 1

The final balanced equation based on the given half-reactions is A) 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O, after combining, balancing electrons, and adding water molecules and hydrogen ions.

Step-by-step explanation:

To complete the final balanced equation based on the given half-reactions, we start by combining the two half-reactions and balancing the electrons to ensure the total number of electrons lost in oxidation equals the number gained in reduction. The oxidation half-reaction, when multiplied by 3, is: 3Cu(s) → 3Cu²⁺(aq) + 6e⁻. The reduction half-reaction, multiplied by 2, is: 2N⁵⁺ + 6e⁻ → 2N²⁺. Next, we add the half-reactions together and balance the hydrogen by adding H⁺ ions. Lastly, water molecules are added to balance the oxygen.

The balanced chemical equation is A) 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O. This equation balances the atoms and charges of all species involved.