Consider a titration of potassium dichromate solution with acidified Mohr's salt solution using diphenyl amine as indicator. The number of moles of Mohr's Salt required per mole of dichromate is:
3
4
5
6
When MnO2 is fused with KOH, a colouredcompound is formed. The product and its colour is:
K2MnO4 , purple colour
Mn2O3 , brown
Mn2O4 , black
KaMnO4 , purple
In [NiCl4]2-, the number of unpaired electrons, are
4
2
3
5
B.
2
In [NiCl4]2- the oxidation number of Ni is +2.
Electronic configuration of Ni (atomic no = 28)
Ni = [Ar] 3d84s2
Ni+2 = [Ar] 3d8
or [Ar]
It is evident that in [NiCl4]2- the number of unpaired electrons are two.
H2C2O4 + KMnO4 in acidic medium reacts to have change in oxidation number of Mn from
7 to 5
2 to 7
5 to 7
7 to 2
For which of the following elements it is difficult to disproportionate in +3 oxidation state ?
N
As
Sb
Bi