MHTCET 14 May 2023 Shift 2 Solved Paper

To determine the oxidation number of platinum $(\mathrm{Pt})$ in the complex ion $\mathrm{PtCl}_6^{2-}$, we need to consider the oxidation numbers of the other atoms in the ion and the overall charge.Chlorine $(\mathrm{Cl})$ is a halogen and typically has an oxidation number of -1 when it's a part of a compound but not in a neutral elemental state.The complex ion $\mathrm{PtCl}_6^{2-}$ has a total charge of -2 . There are six chlorine atoms, each contributing an oxidation number of -1 . This means the total contribution of the chlorines to the charge is $6 \times (-1) = -6$.Now, let's set up an equation to solve for the oxidation number of platinum $(\mathrm{Pt})$, which we'll call $x:$ $x + (6 \times -1) = -2$Solve for $x$ :$\;x - 6 = -2$$\;x = -2 + 6$$\;x = 4$Thus, the oxidation number of platinum in the complex ion $\mathrm{PtCl}_6^{2-}$ is +4 .The correct answer is:Option B: +4