Aqueous sodium hydroxide reacts with an aqueous solution of compound Y to produce a green precipitate. Aqueous ammonia also reacts with an aqueous solution of compound Y to produce a green precipitate. In both reactions, the precipitate remains insoluble in excess reagent. Which ion is present in Y?
- Achromium(III)
- Bcopper(II)
- Ciron(II)
- Diron(III)