Some platinum (IV) complexes were studied by Werner. Which of the following yields maximum number of ions in aqueous solution ?

Options

A. `PtCI_(4)` . `6NH_(3)`
B. `PtCI_(4)` . `4NH_(3)`
C. `PtCI_(4)` . `3NH_(3)`
D. `PtCI_(4)` . `2NH_(3)`

Answer

A

Explanation

In Werner's view, the substance previously represented by the formula `PtC1_(4)` . `6NH_(3)` is compounds of the ion `[Pt(NH_(3))_(6)]^(4+)` , with six `NH_(3)` molecules directly bonded to the Pt atom. The chage of this ion is balanced by four `C1^(-)` ions, giving a neutral compounds with the structural formula `[Pt(NH_(3))_(6)C1_(4)` . According to Werner's theory these complexes should dissolve to give different number of ions per formula unit. For example `[Pt(NH_(3))_(6)]C1_(4)` dissolves to give five ions: `[Pt(NH_(3))_(6)]^(4+)` and four `C1^(-)` ions: Similiary `[Pt(NH_(3))_(4)C1_(2)` dissolves to give three ions: `[Pt(NH_(3))_(4)C1_(2)]^(2+)` and two `C1^(-)` ions. Werner was able to show that the electrical conductions of solutions of these complexes were equal to what was expected for the number of ions predicted by his formulas. He also demonstrated that the chloride ions in the platinum complexes were of tqwo kinds: those that could be precipitated as AgC1 using silver nitrate and those that could not. He explained that the chloride ions within the paltinum complex ion are securely bonded to the metal ion and that only those outside the complex ion can be precipitated with silver nitrate.
1. `[Pt(NH_(3))_(6)]C1_(4) rarr [Pt(NH_(3))_(6)]^(4+) + 4C1^(-)`
2. `[Pt(NH_(3))C1_(2)]C1_(2) rarr [Pt(NH_(3))_(4)C1_(2)]^(2+) + 2C1^(-)`
3. `[Pt(NH_(3))_(3)^(4)C1_(3) rarr [Pt(NH_(3))_(3) C1_(3)]^(+) + C1^(-)`
4. `[Pt(NH_(3))_(2)C1_(4)] rarr` No dissociation