In the electrochemical cell:
\(\mathrm{Z n \left|\right. Z n S O_{4} \left(\right. 0 . 01 M \left.\right) \left|\right. \left|\right. C u S O_{4} \left(\right. 1 . 0 M \left.\right) \left|\right. C u}, \)
the emf of this Daniel cell is E1. When the concentration of ZnSO4 is changed to 1.0 M and that of CuSO4 is changed to 0.01 M, the emf changes to E2. From the following, which one is the relationship between E1 and E2 ?
(Given, \(\frac{RT}{F}\) = 0.059)
1. \(\mathrm{E_{1} < E_{2}}\)
2. \(\mathrm{E_{1} > E_{2}}\)
3. \(\mathrm{E_{2} = 0 \neq E_{1}}\)
4. \(\mathrm{E_{1} = E_{2}}\)
Two half cell reactions are given below:
\(\begin{aligned} &\mathrm{{Co}^{3+}+e^{-} \rightarrow {Co}^{2+}, {E}_{{Co}^{2+} / {Co}^{3+}}^{\circ}=-1.81 {~V}} \\ &2 \mathrm{{Al}^{3+}+6 e^{-} \rightarrow 2 {Al}({s}), {E}_{{Al} / {Al}^{3+}}^{\circ}=+1.66 {~V}} \end{aligned} \)
The standard EMF of a cell with feasible redox reaction will be:
1. | +7.09 V | 2. | +0.15 V |
3. | +3.47 V | 4. | –3.47 V |
The electrode potential for Mg electrode varies according to the equation
\(E_{Mg^{2+}/Mg}\ = \ E_{Mg^{2+}/Mg}^{o} \ - \ \frac{0.059}{2}log\frac{1}{[Mg^{2+}]}\)
The graph of EMg2+ / Mg vs log [Mg2+] among the following is:
1. | 2. | ||
3. | 4. |
Consider the following cell reaction
2Fe(s) + (g) + 4(aq) 2(aq) + 2(l)
E° = 1.67 V, At [] = 10 M, = 0.1 atm and pH = 3, the cell potential at 25 °C is :
1. 1.27 V
2. 1.77 V
3. 1.87 V
4. 1.57 V
1. | –200.27 kJ mol–1 | 2. | –212.27 kJ mol–1 |
3. | –212.27 J mol–1 | 4. | –200.27 J mol–1 |
The value of E0 cell for the following reaction is:
\(Cu^{2+}+ Sn^{2+}\to Cu +Sn^{4+ } \)
(Given, equilibrium constant is 106)
1. | 0.17 | 2. | 0.01 |
3. | 0.05 | 4. | 1.77 |
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 potential of hydrogen electrode in contact with a solution with pH =10, is:
1. | −0.0591 V | 2. | −5.91 V |
3. | 0.0591 V | 4. | −0.591 V |
The most stable oxidized species among the following is:
\(E_{{\mathrm{Cr}_2 \mathrm{O}_7^2}/ \mathrm{Cr}^{3+}}^{o} =1.33 \mathrm{~V} ; E_{\mathrm{Cl}_2 / \mathrm{Cl}^{-}}^{o}=1.36 \mathrm{~V} \)
\( E_{\mathrm{MnO_{4}}^{-} / \mathrm{Mn}^{2+}}^{o}=1.51 \mathrm{~V} ; E_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{o}=-0.74 \mathrm{~V}\)
1. | Cr3+ | 2. | MnO4- |
3. | Cr2O72- | 4. | Mn2+ |
1. | Cu & Zn2+ | 2. | Zn & Cu |
3. | Cu2+ & Zn2+ | 4. | Cu2+ & Zn |