* Redox reaction: This means there's a transfer of electrons between reactants. Copper loses electrons (oxidation) while nitrogen in nitric acid gains electrons (reduction).
* Single displacement reaction: Copper displaces hydrogen from nitric acid, forming copper(II) nitrate and releasing nitrogen dioxide gas.
Here's the balanced chemical equation:
Cu(s) + 4 HNO₃(aq) → Cu(NO₃)₂(aq) + 2 NO₂(g) + 2 H₂O(l)
Explanation:
* Copper (Cu): It is oxidized, losing electrons and forming copper(II) ions (Cu²⁺).
* Nitric acid (HNO₃): The nitrogen in nitric acid is reduced. It gains electrons to form nitrogen dioxide gas (NO₂).
* Copper(II) nitrate (Cu(NO₃)₂): This is formed as the copper ions react with nitrate ions from the nitric acid.
* Nitrogen dioxide (NO₂): This is a reddish-brown gas that is released during the reaction.
* Water (H₂O): This is also formed as a byproduct of the reaction.
Important Note: This reaction only occurs with concentrated nitric acid. Dilute nitric acid will react with copper to produce copper(II) nitrate and nitric oxide (NO) gas instead of nitrogen dioxide.
