The standard values of A, B and C are +0.68 V, - 2.54 V,- 0.50 V respectively. The rder of their reducing power is
A> B >C
A> C > B
C > B > A
B > C > A
The oxidation number of C atom in CH2Cl2 and CCl4 are respectively
-2 and -4
0 and -4
0 and 4
2 and 4
Potassium dichromate is a good oxidising agent in acidic medium, the oxidation state of chromium changes by
2
3
4
5
Which among the following equations represents the reduction reaction taking place in lead accumulator at positive electrode, while it is being used as a source of electrical energy?
Pb → Pb2+
Pb4+ → Pb
Pb2+ → Pb
Pb4+ → Pb2+
When MnO2 is fused with KOH and KNO2 , a coloured compound is formed. Choose the right compound with the appropriate colour.
K2MnO4, green
KMnO4, purple
Mn2O3, brown
Mn3O4, black
Identify the case(s) where there is change is oxidation number
Acidified solution of CrO
SO2 gas bubbled through an acidic solution Cr2O
Alkaline solution of CrO
Ammoniacal solution of CrO
In aqueous solution, Cr2+ is a stronger reducing agent than Fe2+. This is because
Cr2+ ion is more stable than Fe2+
Cr3+ ion with d3 configuration has favourable crystal field stabilisation energy
Cr3+ has half filled configuration and hence more stable
Fe3+ in aqueous solution is more stable than Cr3+