The specific conductance of a 0.1 M KCl solution at 23 is 0.012 .
The resistance of the cell containing the solution at the same temperature
was found to be 55 . The cell constant will be:
1. 0.142 cm-1
2. 0.66 cm-1
3. 0.918 cm-1
4. 1.12 cm-1
Without losing its concentration ZnCl2 solution cannot be kept in contact with.
(1) Au
(2) Al
(3) Pb
(4) Ag
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 h, what mass of aluminium is produced? (Assume 100% current efficiency, atomic mass of Al = 27g 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 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
The Zn acts as sacrificial or cathodic protection to prevent rusting of iron because:
(1) of Zn < of Fe
(2) of Zn > of Fe
(3) of Zn = of fe
(4) Zn is cheaper than iron
What mass of copper will be deposited by passing 2 Faraday of electricity through a solution of Cu(II) salt?
(1) 35.6 g
(2) 63.5 g
(3) 6.35 g
(4) 3.56 g
The same amount of electricity was passed through two cells containing molten Al2O3 and molten NaCl. If 1.8g of Al were liberated in one cell, the amount of Na liberated in the other cell is:
(1) 4.6 g
(2) 2.3 g
(3) 6.4 g
(4) 3.2 g
Standard Reduction electrode potential of three metals X, Y and Z are -1.2V, + 0.5V and -3V respectively. The reducing power of these metals will be
(1) Y>X>Z
(2) Z>X>Y
(3) X>Y>Z
(4) Y>Z>X
How many columbs of electricity are consumed when 100 mA current is passed through a solution of AgNO3 for 30 minute during an electrolysis experiment?
(1) 108
(2) 18000
(3) 180
(4) 3000
Standard reduction potentials at 25C of Li+/Li, Ba2+/Ba, Na+/Na and Mg2+/Mg are -3.05, -2.90, -2.71 and -2.37 V respectively. Which one of the following is the strongest oxidising agent ?
(1) Mg2+
(2) Ba2+
(3) Na+
(4) Li+