For the redox reaction
Zn (s) + Cu2+ (0.1 M) → Zn2+ (1 M) + Cu (s)
taking place in a cell, E is 1.10 V. Ecell for the cell will be
2.14 V
1.80 V
1.07 V
0.82 V
The highest electrical conductivity of the following aqueous solutions is of
0.1 M difluoroacetic acid
0.1 M fluoroacetic acid
0.1 M chloroacetic acid
0.1 M acetic acid
Aluminium oxide may be electrolysed at 1000°C to furnish aluminium metal (atomic mass = 27 amu; 1 F = 96,500 C). The cathode reaction is
Al3+ + 3e- → Al0
To prepare 5.12 kg of aluminium metal by this method would require
5.49 × 101 C of electricity
5.49 × 104 C of electricity
1.83 × 107 C of electricity
5.49 × 107 C of electricity
In acidic medium MO is converted to Mn2+. The quantity of electricity in faraday required to reduce 0.5 mole of MnO to M2+ would be:
2.5
5
1
0.5
During electrolysis of water the volume of O2 liberated is 2. 24dm3. The volume of hydrogen liberated, under same conditions will be
2.24 dm3
1.12 dm3
4.48 dm3
0.56 dm3
The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is (Atomic mass of Al = 27)
180 kg
270 kg
540 kg
90 kg
The best way to prevent rusting of iron is
making it cathode
putting in saline water
Both (a) and (b)
none of the above
A.
making it cathode
During rusting, oxidation of iron takes place, i.e., it acts as anode. Hence, coating/connecting iron with metal of lower reduction potential ( in comparison to iron) is the best way to prevent its rusting. In this process, the metal with low reduction potential undergoes oxidation(i.e, acts as anode) while iron acts as cathode. ( cathodic protection). Use saline water accelerates the process of rusting thereby increasing the electric conduction of electrolyte solution formed on the metal surface.