The mass of copper deposited from a solution of Cu2S by passing a current of 2.5 ampere for 6 minute is
0.3 g
0.5 g
0.7 g
0.9 g
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)
The oxidation number of Cr in [Cr(NH3)6]Cl3 is
8
6
4
3
The oxidation number of As in H2AsO4- is
7
5
9
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
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
In an electrolytic cell, the flow of electrons is from
cathode to anode in the solution
cathode to anode through external supply
cathode to anode through internal supply
anode to cathode through internal supply
Which of the following metal has the highest tendency for the half-cell reaction?
sodium
lithium
potassium
cesium
Faraday constant
is a numerical constant
depends on equivalent
depends upon the current passed
depends on the number of electrons
In which of the following reaction, ozone acts as a reductant?
Ag2O + O3 → 2Ag + 2O2
KNO2 + O3 → KNO3 + O2
PbS + 4O3 → PbSO4 + 4O2
Na3AO3 + O3 → Na3AsO4 + O2
