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
4.5 g of aluminium (at. mass 27 u) 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
44.8 L
22.4 L
11.2 L
5.6 L
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
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
Without losing its concentration ZnCl2 solution cannot be kept in contact with
Au
Al
Pb
Ag
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
A hypothetical electrochemical cell is shown below
A | A+ (xM) || B+ (yM) | B
The emf measured is + 0.20 V. The cell reaction is
A + B+ → A+ + B
A+ + B → A + B+
A+ + e- → A; B+ + e- → B
The cell reaction cannot be predicted
Cell reaction is spontaneous when
Eored is negative
Eored is positive
ΔGo is negative
ΔGo is positive
EoFe2+/Fe = -0.441 V and EoFe3+/Fe2+ = 0.771 V,
the standard emf of the reaction
Fe + 2 Fe3+ → 3 Fe2+ will be
0.111 V
0.330 V
1.653 V
1.212 V
The efficiency of a fuel cell is given by
ΔG / ΔS
ΔG / ΔH
ΔS / ΔG
ΔH / ΔG
