Oxidation state of Cu in [Cu(NH₃)₄]²⁺:
A0
B+1
C+3
D+2 (charge of complex - 4 × 0 (NH₃) = +2)
Answer & Solution
Correct answer: D. +2 (charge of complex - 4 × 0 (NH₃) = +2)
NH₃ neutral. Charge on complex +2 = ox of Cu. Cu²⁺ is d⁹ (Jahn-Teller distortion). Deep blue color due to d-d transition.
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