Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.0 x 104 A of current is passed through molten Al2O3 for 6 hours, the mass of aluminum produced is:
(Assume 100 % current efficiency, the atomic mass of Al = 27 g mol-1)
1. | 9.0 x 103 g | 2. | 8.1 x 104 g |
3. | 2.4 x 105 g | 4. | 1.3 x 104 g |
The molar conductance of solution of a weak monobasic acid is 8.0 ohm-1 cm2 and at infinite dilution is 400 ohm-1 cm2. The dissociation constant of this acid is:
1. | \(1.25 \times10^{-5}\) | 2. | \(1.25 \times10^{-6}\) |
3. | \(6.25 \times10^{-4}\) | 4. | \(1.25 \times10^{-4}\) |
Given:
(i) Eo = 0.337 V
(ii) Eo = 0.153 V
Electrode potential, Eo for the reaction,
, will be:
1. 0.52 V
2. 0.90 V
3. 0.30 V
4. 0.38 V
Kohlrausch's law states that at:
1. | Finite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte. |
2. | Infinite dilution, each molecule makes definite contribution to equivalent conductance of an electrolyte depending on the nature of the other ion of the electrolyte. |
3. | Finite dilution, each molecule makes definite contribution to conductance of an electrolyte whatever be the nature of the other ion of the electrolyte. |
4. | Infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte. |
A steady current of 1.5 A flows through a copper voltmeter for 10 min. If the electrochemical equivalent of copper is 30 × 10-5 g C-1, the mass of copper deposited on the electrode will be:
1. 0.40 g
2. 0.50 g
3. 0.67 g
4. 0.27 g
For a given reaction,
Cu(s) + 2Ag+ (aq) → Cu2+(aq)+2Ag(s);
E0=0.46 V at 298 K . The equilibrium constant will be :
1. | 2. | ||
3. | 4. |
1. | 17.6 mg | 2. | 21.3 mg |
3. | 24.3 mg | 4. | 13.6 mg |
If = -0.441 V and = 0.771 V, the standard emf of the reaction:
Fe + 2Fe3+→ 3Fe2+ will be:
1. | 0.330 V | 2. | 1.653 V |
3. | 1.212 V | 4. | 0.111 V |
A hypothetical electrochemical cell is shown below.
A|A+(x M) || B+(y M)|B
The Emf measured is +0.20 V. The cell reaction is:
1. A+ + B → A + B+
2. A+ + e- → A ; B+ + e- → B
3. The cell reaction cannot be predicted.
4. A + B+ → A+ + B
Given the following cell reaction:
\(\mathrm{2Fe^{3+}(aq) \ + \ 2I^{-}(aq)\rightarrow 2Fe^{2+}(aq) \ + \ I_{2}(aq)}\)
\(E_{cell}^{o} \ = \ 0.24 \ V\) at .
The standard Gibbs energy ∆rG⊝ of the cell reaction is:
[Given: ]
1.
2.
3.
4.