On the basis of the information available from the reaction
4/3 Al + O2 → 2/3 Al2O3, ΔG = - 827 KJ mol-1 of O2 , the minimum emf required to carry out the electrolysis of Al2O3 is (F = 96500 C mol-1)
2.14 V
4.28 V
6.42 V
8.56 V
Without losing its concentration ZnCl2 solution cannot be kept in contact with
Au
Al
Pb
Ag
On the basis of the following Eo values, the strongest oxidising agent is
[Fe(CN)6]4-
Fe2+
Fe3+
[Fe(CN)6]3-
Which one of the following pairs of substances on reaction will not evolve H2 gas?
Iron and H2SO4 (aqueous)
Iron and Steam
Copper and HCl (aqueous)
Sodium and Ethyl alcohol
The efficiency of a fuel cell is given by
ΔG / ΔS
ΔG / ΔH
ΔS / ΔG
ΔH / ΔG
Kohlrausch's law states that at
Finite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.
Infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte depending on the nature of the other ion of the electrolyte.
Infinite dilution, each ion makes definite contribution to conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.
Infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.
The equivalent conductance of Ba2+ and Cl- are 127 and 76 ohm-1 cm-1 eq-1 respectively at infinite dilution. The equivalent conductance of BaCl2 at infinite dilution will be
139.52
203
279
101.5
Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.0 × 104 A of current is passed through molten Al2O3 for 6 hours, what mass of aluminium is produced? (Assume 100% current efficiency, at mass of Al = 27 g mol-1)
9.0 × 103 g
8.1 × 104 g
2.4 × 105 g
1.3 × 104 g
Cell reaction is spontaneous when
Eored is negative
Eored is positive
ΔGo is negative
ΔGo is positive
An electrochemical cell is shown below
Pt, H2 (1 atm) |HCl (0.1 M)| CH3COOH(0.1 M)| H2 (1 atm), Pt. the emf of the cell will not be zero, because
emf depends on molarities of acids used
pH of 0.1 M HCl and 0.1 M CH3CHOOH is not same
The temperature is constant
Acids used in two compartments are different
