In which of the following reaction, hydrogen is acting as an oxidizing agent?
with S to give H2S
with I2 to give HI
with Li to form LiH
with Cl to give HCl
H2O2 is
a catalyst
An oxidizing agent
A reducing agent
Both '2' and '3'
The amount of mercury deposited by passing 300 C of charge through mercurous sulphate solution is (Take atomic weight of mercury as 200)
0.2 g
0.4 g
0.6 g
0.8 g
The standard e.m.f of a cell, involving one electron change is 0.591 V 25oC. The equilibrium constant of the reaction is (F = 96500 C-mol-1; R = 8.314 J - K-1 - mol-1)
1.0 × 101
1.0 ×105
1.0 ×1010
1.0 ×1030
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
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)
0.3 g
0.5 g
0.7 g
0.9 g
The mass of copper deposited from a solution of Cu2S by passing a current of 2.5 ampere for 6 minute is
In which cell, free energy of a chemical reaction is directly converted into electricity?
Fuel cell
Leclanche cell
Concentration cell
Lead storage cell
For the redox reaction : Zn(s) + Cu2+ (0.1 M) → Zn2+ (1 M) + Cu(s) taking place in a cell, Eo cell is 1.1 volt. Calculate the value of Ecell for the cell?
2.14 volt
1.80 volt
1.07 volt
0.82 volt
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)