Question:

The surface of copper gets tarnished by the formation of

Last updated: 7/4/2023

The surface of copper gets tarnished by the formation of

The surface of copper gets tarnished by the formation of copper oxide N2 gas was passed to prevent the oxide formation during heating of copper at 1250 K However the N gas contains 1 mole of water vapour as impurity The water vapour oxidises copper as per the reaction given In PH PM 0 below 2Cu s H O g Cu O s H g PH is the minimum partial pressure of H in bar needed to prevent the oxidation at 1250 K The value of In PH is Given total pressure 1 bar R universal gas constant 8 J K 1 mol In 10 2 3 Cu s and Cu O s are mutually immiscible At 1250 K 2Cu s 2O2 g Cu O s AG 78 000 J mol 1 H2 g O2 g H O g AGe 1 78 000 J mol G is the Gibbs energy 2018