Identify the two statements which are incorrect regarding Corrosion of Iron. A. During electrical protection of underground Iron pipes from corrosion the connected Mg plate undergoes reduction. B. At the Cathodic area on Iron the reaction occurring is 4 H ⁺+ O ₂+4 e 2 H ₂ O C. Rust formed Fe ₂ O ₃ . xH ₂ O is an acidic oxide. D. The H ⁺ ions are obtained from water containing dissolved gases like SO ₂, NO ₂ or CO ₂ .

Step-by-step solution

In the process of cathodic protection of iron pipes, a more reactive metal like magnesium is used as a sacrificial anode. The magnesium undergoes oxidation ( Mg Mg²⁺ + 2e⁻ ) to protect the iron. Therefore, statement A is incorrect because Mg undergoes oxidation, not reduction. At the cathodic area of iron corrosion, oxygen is reduced in the presence of moisture. The reaction is O₂ + 4H⁺ + 4e⁻ 2H₂O . This is a standard cathodic reaction in acidic or neutral media, making statement B correct. Rust is hydrated iron(II