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 |
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
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 |
The molar conductance of NaCl, HCI, and CH3COONa at infinite dilution are 126.45, 426.16, and 91.0 S cm mol–1 respectively. The molar conductance of CH3COOH at infinite dilution will be:
1. 698.28 S cm2 mol–1
2. 540.48 S cm2 mol–1
3. 201.28 S cm2 mol–1
4. 390.71 S cm2 mol–1
The molar conductivity of 0.007 M acetic acid is 20 S cm2 mol–1. The dissociation constant of acetic acid is :
(\(\mathrm{\Lambda_{H^{+}}^{o} \ = \ 350 \ S \ cm^{2} \ mol^{-1} }\))
(\(\mathrm{\mathrm{\Lambda_{CH_{3}COO^{-}}^{o} \ = \ 50 \ S \ cm^{2} \ mol^{-1} }}\))
1. mol L–1
2. mol L–1
3. mol L–1
4. mol L–1
The standard Emf of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 25 ºC. The equilibrium constant of the reaction would be:
(Given F = 96500 C mol–1; R = 8.314 J K–1 mol–1)
1. 4.0 × 1012
2. 1.0 × 102
3. 1.0 × 1010
4. 2.0 × 1011
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 |
A cell reaction become spontaneous when:
1. ∆Gº is negative
2. ∆Gº is positive
3. is positive
4. is negative
For the disproportionation of copper:
2Cu+ → C u2+ + C u is:
(Given for Cu+2/Cu is 0.34 V & Eº for Cu+2/Cu+ is 0.15 V )
1. 0.49 V
2. – 0.19 V
3. 0.38 V
4. – 0.38 V
4.5 g of aluminium (at. mass = 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H+ ions in solution by the same quantity of electric charge will be:
1. | 44.8 L | 2. | 11.2 L |
3. | 22.4 L | 4. | 5.6 L |