CBSE
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
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
Strongest Bronsted base among the following anions is
Cl
Cl
Cl
ClO-
The colourless species is
VCl3
VOSO4
Na3VO4
[V(H2O)6]SO4.H2O
Substances that are oxidised and reduced in the following reaction are respectively
N2H4 (l) + 2H2O2 (l) N2 (g) + 4H2O (l)
N2H4, H2O
N2H4, H2O2
N2, H2O2
H2O, N2
Which of the following is most powerful oxidising agent?
I2
Cl2
Br2
F2
For which of the following elements it is difficult to disproportionate in +3 oxidation state ?
N
As
Sb
Bi
In [NiCl4]2-, the number of unpaired electrons, are
4
2
3
5
Oxidation number Fe in K3 [FeCN)6] is
+1
+2
+3
+4
Oxidation number of Cr in K2Cr2O7 is
2
4
6
7