H2O2 is
a catalyst
an oxidising agent
a reducing agent
both '2' and '3'
Which of the following reaction does not involve either in oxidation or reduction?
Cr → CrCl3
Na → Na+
2S2O32- → S4O62-
K2CrO4 → K2CrO7
In which cell, free energy of a chemical reaction is directly converted into electricity?
fuel cell
lechlanche cell
concentration cell
lead storage battery
If emf of the cell Zn| Zn2 (0.01 M)| | Fe2+ (0.001 M) | Fe at 298 K is 0.2957, then the value of equilibrium constant for the cell reaction is?
Aluminium oxide is electrolysed to obtain aluminium metal (At. weight = 27 a.m.u.; 1 Faraday = 96,500 C). The cathode reaction is Al3+ + 3e- →AloTo prepare 5.12 kg of aluminium metal by this method would require
5.49 × 107C of electricity
1.83 × 107C of electricity
5.49 × 104C of electricity
5.49 × 101C of electricity
For standard reduction potentials of three metals A, B and C are +0.5 V, -3.0 V and -1.2 V respectively. The reducing powers of these metals are
B > C > A
A > B > C
C > B > A
A > C > B
The oxidation number of chromium in potassium dichromate is
+ 2
- 2
- 5
+ 6
What is the oxidation number of iron in the compound [Fe(H2O)5(NO)+]2+
+ 1
+ 4
+ 5
+ 7
The e.m.f of a galvanic cell with electrode potentials of silver equal to + 0.80 V and that of copper equal to + 0.34 V is
-0.46 V
-1.14 V
+0.46 V
+ 1.14 V
The standard e.m.f of a galvanic cell, with standard electrode potentials of zinc equal to -0.76 V and that of copper equal to + 0.34 V, is
+ 0.76 V
+ 1.1 V
- 0.34 V
- 1.1 V
