Electrochemistry

Standard electrode potential of three metals X, Y and Z are -1.2 V, +0.5 V and -3.0 V respectively. The reducing power of these metals will be

1. Y > Z > X
2. Y > X > Z
3. Z > X > Y
4. X > Y > Z

The electrode potentials for Cu2+(aq) + e- Cu+(aq) and Cu+(aq) + e- Cu(s) are +0.15 V and +0.50 V respectively. The value of E Cu2+/Cu will be

1. 0.500 V
2. 0.325 V
3. 0.650 V
4. 0.150 V

Standard electrode potential for Sn4+/Sn2+ couple is +0.15 V and that for the Cr3+/Cr couple is -0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be

1. +1.19 V
2. +0.89 V
3. +0.18 V
4. +1.83 V

Which of the following expressions correctly represents the equivalent conductance at infinite dilution of Al2(SO4)3. Given that Al3+ and SO42- are the equivalent conductances at infinite dilution of the respective ions?

1. 2 Al3+ + 3 SO42-
2. Al3+ + SO42-
3. ( Al3+ + SO42-) 6
4. 13 Al3+ + 12 SO42-

Consider the following relations for emf of an electrochemical cell (i) EMF of cell = (Oxidation potential of anode) − (Reduction potential of cathode) (ii) EMF of cell = (Oxidation potential of anode) + (Reduction potential of cathode) (iii) EMF of cell = (Reduction potential of anode) + (Reduction potential of cathode) (iv) EMF of cell = (Oxidation potential of anode) − (Oxidation potential of cathode) Which of the above relations are correct?

1. (iii) and (i)
2. (i) and (ii)
3. (iii) and (iv)
4. (ii) and (iv)

For the reduction of silver ions with copper metal, the standard cell potential was found to be +0.46 V at 25 C. The value of standard Gibbs energy, G will be (F = 96500 C mol-1)

1. -89.0 kJ
2. -89.0 J
3. -44.5 kJ
4. -98.0 kJ

An increase in equivalent conductance of a strong electrolyte with dilution is mainly due to

1. increase in ionic mobility of ions
2. 100% ionisation of electrolyte at normal dilution
3. increase in both i.e., number of ions and ionic mobility of ions
4. increase in number of ions.

Given : (i) Cu2+ + 2e- Cu, E = 0.337 V (ii) Cu2+ + e- Cu+, E = 0.153 V Electrode potential, E for the reaction, Cu+ + e- Cu, will be

1. 0.90 V
2. 0.30 V
3. 0.38 V
4. 0.52 V

Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.0 104 amperes of current is passed through molten Al2O3 for 6 hours, what mass of aluminium is produced? (Assume 100% current efficiency, at. mass of Al = 27 g mol-1).

1. 8.1 104 g
2. 2.4 105 g
3. 1.3 104 g
4. 9.0 103 g

The equivalent conductance of M/32 solution of a weak monobasic acid is 8.0 mho cm2 and at infinite dilution is 400 mho cm2. The dissociation constant of this acid is

1. 1.25 10-6
2. 6.25 10-4
3. 1.25 10-4
4. 1.25 10-5