Given below are the half-cell reactions,
Mn2+ + 2e-
Mn will be:
E0 for Fe2+ + 2e → Fe is -0.44 volt and E0 for Zn2+ + 2e→ Zn is -0.76 volt, thus:
1. Zn is more electropositive than Fe
2. Fe is more electropositive than Zn
3. Zn is more electronegative
4. none of the above
The voltage of the cell given below increases with:
Cell: Sn(s) + 2Ag+(aq) → Sn2+(aq) + 2Ag(s)
1. Increase in size of the silver rod.
2. Increase in the concentration of Sn2+ ions.
3. Increase in the concentration of Ag+ ions.
4. None of the above.
, the standard emf of the reaction
will be
1. 0.111V
2. 0.330V
3. 1.653V
4. 1.212V
The 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. | +0.89 V | 2. | +0.18 V |
3. | +1.83 V | 4. | +1.199 V |
If an iron rod is dipped in CuSO4 solution, then:
1. Blue colour of the solution turns red.
2. Brown layer is deposited on iron rod.
3. No change occurs in the colour of the solution.
4. None of the above.
Without losing it's concentration, ZnCl2 solution cannot be kept in contact with :
1. Au
2. Al
3. Pb
4. Ag
The standard reduction potential at 290 K for the following half reactions are,
(i) Zn2+ + 2e— → Zn(s); E° = -0.762 V
(ii) Cr3+ + 3e → Cr(s); E° = -0.740 V
(iii) 2H+ + 2e → H2(g); · E° = +0.000 V
(iv) Fe3+ + e → Fe2+; E° = +0.77V
Which is the strongest reducing agent?
1. Zn
2. Cr
3. Fe2+
4. H2
Which graph correctly correlates Ecell as a function of concentrations for the cell (for different values of M and M') ?
1. 2.
3. 4.
The most convenient method to protect the bottom of the ship made of iron is
1. coating it with red lead oxide
2. white tin plating
3. connecting it with Mg block
4. connecting it with Pb block