Formula of hexaaqua manganese (II) phosphate is
[Mn(H2O)]6PO4
[Mn(H2O)6]3PO4
[Mn(H2O)6]3(PO4)2
[Mn(H2O)6](PO4)3
Which transition element of the following outermost electronic configuration shows the highest oxidation state?
3d3, 4s2
3d5, 4s1
3d5, 4s2
3d6, 4s2
Which of the following is not a method of preparation of colloidal solution?
Electrical dispersion
Peptization
Coagulation
Mechanical dispersion
What is the magnetic moment value of Fe2+ ion in [Fe(CN)6]4- ?
0
C.
Let the oxidation state of Fe be x in [Fe(CN)6]4-
x + (-1)6 = -4
x = -4 + 6 = +2
Fe(26) = [Ar] 3d6 4s2
Fe2+ = [Ar] 3d6
i.e. n = 4
We know that, magnetic moment,
μ =
=
=
The standard reduction potential E° for half-reactions are
Zn → Zn2+ + 2e- ; E° = +0.76 V
Fe → Fe2+ + 2e- ; E° = +0.41 V
The EMF of the cell reaction
Fe2+ + Zn → Zn2+ + Fe is
+1.28 V
-1.28 V
+0.35 V
-0.35 V
The lanthanoid contraction is responsible for the fact that
Zn and Y have about same radius
Zr and Nb have similar oxidation states
Zr and Hf have about the same radius
Zr and Zn have the same oxidation state