MHTCET 15 May 2024 Shift 2 Paper

Concept:A cationic complex is a coordination compound in which the complex ion carries a positive charge.Explanation:To identify the cationic complex, examine the charge on the inner coordination sphere in each option.Option A: $\mathrm{Na}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$ dissociates into $\mathrm{Na}^{+}$ and $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}$, so the complex ion is negatively charged. It is an anionic complex.Option B: $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right] \mathrm{SO}_{4}$ dissociates into $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right]^{+}$ and $\mathrm{SO}_{4}^{2-}$. Since the complex ion has a positive charge, it is a cationic complex.Option C: $\left[\mathrm{Ni}(\mathrm{CO})_{4}\right]$ has neutral $\mathrm{CO}$ ligands and a zero charge on nickel, making it a neutral complex.Option D: $\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$ dissociates into $\mathrm{K}^{+}$ and $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}$, so the complex ion is negatively charged. It is an anionic complex.Thus, the only compound containing a positively charged complex ion is Option B.Answer:Option B: $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right] \mathrm{SO}_{4}$