Which of the following has been universally accepted as a reference electrode at all temperatures, and has been assigned a value of zero volt?
zinc electrode
copper electrode
graphite electrode
standard hydrogen electrode
The mass of copper deposited from a solution of CuSO4 by passing a current of 5 A for 15 min is (Atomic Wt. of copper = 63.5)
2.96 g
1.48 g
1.87 g
2.89 g
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
Which of the following reaction is used to make a fuel cell?
2H2(g) + O2(g) → 2H2O(I)
2Fe(s) + O2(g) + 4H+(aq) → 2Fe2+(aq) + 2H2O(I)
Pb(s) + PbO2(s) + 2H2SO4(aq) →2PbSO4(s) + 2H2O(I)
Cd(s) + 2Ni(OH)3(s) → CdO(s) + 2Ni(OH)2(s) + H2O(I)
What is the single electrode potential of zinc electrode in 0.01 M ZnSO4 solution at 25oC (Eo = -0.76 V)?
-0.82 V
-1.82 V
-2.82 V
-3.82 V
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
A smuggler could not carry gold by depositing iron on the gold surface, because
iron rusts
gold is denser
gold has lower standard reduction potential than iron
gold has higher standard reduction potential than iron
The EoM3+/M2+ values for Cr, Mn, Fe and Co are -0.41 V, + 1.57 V, +0.77 V and +1.97 V respectively. For which one of the metals, the change in oxidation state from +2 to +3 will be easiest?
Cr
Co
Fe
Mn
Among the properties (a) reducing (b) oxidising (c) complexing the set of properties shown by CN- ion towards metal species is
a, b
a, c
b, c
a, b, c
Which of the following metal has the highest tendency for the half-cell reaction?
sodium
lithium
potassium
cesium
