AI2O3 is reduced by electrolysis at low potentials and high currents. If 4.0 x 104 A of current is passed through moleten AI2O3 for 6 h, what mass of aluminium is produced ? (Assume 100% current efficiency, at mass ofAI = 27 g mol-1)
9.0 x 103g
8.1 x 104g
2.4 x 105g
1.3 x 104g
The efficiency of a fuel cell is given by.
An electrochemical cell is shown below.Pt,H2[1atm]HCI (0.1M)CH3COOH(0.1M)H2(1atm),Pt.
Emf depends on molarities of acids used.
pH of 0.1 M HCI and 0.1 M CH3COOH is not same
The temperature is constant.
Acids used in two compartments are different.
Equivalent conductance of NaCI, HCI and C2H5COONa at infinte dilution are 126.45 ,426.16 and 91 ohm-1 cm2, respectively. The equivalent conductance of C2H5COOH is.
201.28 ohm-1 cm2
390.71 ohm-1 cm2
698.28 ohm-1 cm2
540.48 ohm-1 cm2
The equivalent conductances of Ba2+ and Cl- are 127 and 76 ohm-1 cm-1 eq-1 respectively at infinite dilution. The equivalent conductance of BaCI2 at infinite dilution will be.
139.52
203
279
101.5
The equivalent conductance of solution of a weak monobasic acid is 8.0 mho cm2 and at infinite dilution is 400 mho cm2.
1.25 x 10-5
1.25 x 10-6
6.25 x 10-4
1.25 x 10-4
Standard electrode potentials are
Fe3+ increases
Fe3+ decreases
remains unchanged
Fe2+ decreases
On heating one end of a piece of a metal, the other end becomes hot because of.
Energised electrons moving to the other end.
Resistance of the metal.
Mobility of atoms in the metal.
Minor perturbation in the energy of atoms
The most convenient method to protect the bottom of the ship made of iron is.
Coating it with red lead oxide.
White tin plating.
Connecting it with mg block.
Connecting it with Pb block.
In electrolysis of NaCI when Pt electrode is taken then H2 is liberated at cathode while with Hg cathode it forms sodium amalgam because.
Hg is more inert than Pt.
More voltage is required to reduce H+ at Hg than at Pt.
Na is dissolved in Hg while it does not dissolved in Pt.
Concentration of H+ ions is larger when Pt electrode is taken.
