Calculate the number of unpaired electrons in following gaseous ions: Mn3+, Cr3+, V3+ and Ti3+, which one of these is the most stable in aqueous solution?
The number of unpaired electrons can be determined from their electronic configurations and are tabulated below:
Specie |
Electronic configuration |
No. of unpaired electron |
1. Mn3+ |
[Ar] 3d44s0 |
4 |
2. Cr3+ |
[Ar] 3d34s0 |
3 |
3. V3+ |
[Ar] 3d24s0 |
2 |
4. Ti3+ |
[Ar] 3d14s0 |
1 |
Out of these, Cr3+ is most stable in aqueous solution as its hydration energy is highest
.