MHTCET 14 May 2023 Shift 2 Solved Paper

The term "anionic sphere complex" refers to a complex ion that carries a net negative charge. To identify an anionic sphere complex among the options provided, we need to look at the complex ions and see which ones are negatively charged.Option A: Hexaamminecobalt(III) chloride. This complex is $[\mathrm{Co}(\mathrm{NH}_3)_6]^{3+}$ and carries a net positive charge. Therefore, it is not an anionic sphere complex.Option B: Potassium hexacyanoferrate(II). This complex is $[\mathrm{Fe}(\mathrm{CN})_6]^{4}$, which carries a net negative charge. Therefore, it is an anionic sphere complex.Option C: Tetraamminedichlorocobalt(III) ion. This complex ion is $[\mathrm{Co}(\mathrm{NH}_3)_4\mathrm{Cl}_2]^{+}$, which carries a net positive charge. Thus, it is not an anionic sphere complex.Option D: Pentaamminechlorocobalt(III) sulphate. This complex itself is $[\mathrm{Co}(\mathrm{NH}_3)_5\mathrm{CI}]^{2+}$ and carries a net positive charge. So, it is not an anionic sphere complex. The correct answer is Option B: Potassium hexacyanoferrate(II), which features the anionic complex $[\mathrm{Fe}(\mathrm{CN})_6]^{4-}$.