Q. No.Zn(s) + Ag2O(s) + H2O(l) \(\rightleftharpoons\) 2Ag(s) + Zn2+(aq) + 2OH–(aq)
If half-cell potentials are-
| Zn2+(aq) + 2e–→ Zn(s) | Eo = – 0.76 V |
| Ag2O(s) + H2O(l) + 2e– → 2Ag(s) + 2OH–(aq) |
Eo = 0.34 V |
The cell potential will be:
| 1. | 0.42 V | 2. | 0.84 V |
| 3. | 1.34 V | 4. | 1.10 V |
\(\text{Mn}^{2+}+2e^-\rightarrow \text{Mn},\ E^{0}= -1.18~ \text V \)
\(\text{Mn}^{2+}\rightarrow \text{Mn}^{3+}+e^-,\ E^{0}= -1.51~ \text V \)
The \(E^{0}\) for the reaction \(\mathrm{3\ Mn^{2+}\rightarrow Mn^{0}+2Mn^{3+} }\) and possibility of the forward reaction are respectively:
| 1. | –4.18 V and Yes | 2. | +0.33 V and Yes |
| 3. | +2.69 V and No | 4. | –2.69 V and No |
| 1. | Y > X > Z | 2. | Z > X > Y |
| 3. | X > Y > Z | 4. | Y > Z > X |
| Cu2+(aq) + e- → Cu+(aq) | 0.15 V |
| Cu+(aq) + e- → Cu(s) | 0.50 V |
The value of \(E_{Cu^{2+}/Cu}^{o}\) will be:
| 1. | 0.325 V | 2. | 0650 V |
| 3. | 0.150 V | 4. | 0.500 V |
What is the standard cell potential when the Sn⁴⁺/Sn²⁺ (E° = +0.15 V) and Cr³⁺/Cr (E° = −0.74 V) half-cells are connected under standard conditions?
1. +0.89 V
2. +0.18 V
3. +1.83 V
4. +1.199 V
Consider the following relations for emf of an electrochemical cell:
| (a) | emf of a cell = (Oxidation potential of the anode) – (Reduction potential of the cathode) |
| (b) | emf of a cell = (Oxidation potential of the anode) + (Reduction potential of the cathode) |
| (c) | emf of a cell = (Reduction potential of the anode) + (Reduction potential of the cathode) |
| (d) | emf of a cell = (Oxidation potential of the anode) – (Oxidation potential of the cathode) |
Which of the following combinations correctly represents the relation for the emf of the cell?
| 1. | (a) and (b) | 2. | (c) and (d) |
| 3. | (b) and (d) | 4. | (c) and (a) |
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 |
Consider the following reaction:
\(\frac{4}{3} \mathrm{Al}(\mathrm{s})+\mathrm{O}_2(\mathrm{~g}) \rightarrow \frac{2}{3} \mathrm{Al}_2 \mathrm{O}_3(\mathrm{~s})\)
The minimum e.m.f. required to carry out the electrolysis of Al2O3 is:
(F = 96500 C mol–1)
1. 2.14 V
2. 4.28 V
3. 6.42 V
4. 8.56 V
The EMF of a Daniel cell at 298 K is E1 Zn|ZnSO4(0.01 M) || CuSO4(1.0 M)|Cu.
When the concentration of ZnSO4 is 1.0 M and that of CuSO4 is 0.01 M, the EMF is changed to E2. The correct relationship between E1 and E2 is:
| 1. | E1 > E2 | 2. | E1 < E2 |
| 3. | E1 = E2 | 4. | E2 = 0 ≠ E1 |
In electrolysis of NaCl when Pt electrode is taken then H2 is liberated at the cathode while with Hg cathode it forms sodium amalgam because:
| 1. | Hg is more inert than Pt |
| 2. | More voltage is required to reduce H+ at Hg than at Pt |
| 3. | Na is dissolved in Hg while it does not dissolve in Pt |
| 4. | The concentration of H+ ions is larger when the Pt electrode is taken |
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