Number of unpaired electrons in Mn4+ is :
3
5
6
4
A.
3
The electronic configuration of
Mn (25) = 1s2 , 2s2 2p6 , 3s2 3p6 3d5 , 4s2
The electronic configuration of
Mn4+ (25 - 4 = 21) = 1s2 , 2s2 2p6 , 3s2 3p6 3d3 , 4s0
Thus , Mn4+ has three unpaired electrons .
If hydrogen electrode dipped in two-solution of pH = 3 and pH = 6 and salt bridge is connected , the emf of resulting cell is :
0.177 V
0.3 V
0.052 V
0.104 V