`S_(1) : Mn^(2+)` compounds more stable than `Fe^(2+)` towards oxidation to their `+3` state.
`S_(2)` : Titanium and copper both in the first series of transition metals exhibits `+1` oxidation state most frequently.
`S_(3) : Cu^(+)` ions is stable in aqueous solutions.
`S_(4)` : The `E^(0)` value for the `Mn^(3+)//Mn^(2+)` couple much more positive than that for `Cr^(3+)//Cr^(2+)` or `Fe^(3+)//Fe^(2+)`,

Options

A. `T TFT`
B. `TFFT`
C. `TFT T`
D. `FFTF`

Answer

B

Explanation

`S_(1)` : It is because `Mn^(2+)` has `3d^(5)` configuration which has extra stability.
`S_(2)` : Not Titanium but Copper, because with `+1` oxidation state an extra stable configuration `3d^(10)` results.
`S_(3)` : Not stable as it undergoes disproportionation `2cu^(+) (aq) rarr Cu^(2+)(aq) + Cu(s)`. The `E^(0)` value for this is favourable.
`S_(4)` : Much larger third ionisation energy of Mn (where the required change id `d^(5)` to `d^(4)`) is mainly responsible for this. This also explains why the `+3` state of Mn is of little importance.