Consider the following statements regarding the stability and redox behaviour of transition metal ions in aqueous solutions: (A) Cr ²⁺ is strongly reducing in nature as it achieves a stable d^3 ( t_ 2g ^3 ) configuration upon oxidation. (B) Mn ³⁺ is strongly oxidising in nature as it achieves a stable d^5 configuration upon reduction. (C) Copper exhibits a highly stable +1 oxidation state in aqueous solution due to i

Step-by-step solution

(A) is correct. Cr ²⁺ ( d^4 ) is a strong reducing agent because its oxidation to Cr ³⁺ yields a stable half-filled t_ 2g ^3 configuration in an octahedral field. (B) is correct. Mn ³⁺ ( d^4 ) is a strong oxidising agent because its reduction to Mn ²⁺ yields a stable half-filled d^5 configuration. (C) is incorrect. Despite having a d¹⁰ configuration, Cu ^+ is unstable in aqueous solution and undergoes disproportionation into Cu ²⁺ and Cu . This is driven by the much higher negative hydration enthalpy of Cu ²⁺ which