The standard emf of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 25o C. The equilibrium constant of the reaction would be.
(Given F = 96500 C mol-1; R =8.314 JK-1 mol-1)
2.0 x1011
4.0 x 1012
1.0 x 102
1.0 x 1010
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
Given,
0.52 V
0.90 V
0.30 V
0.38 V
Which one of the following pairs of substances on reaction will not evolve H2 gas.
Iron and H2SO4 (aqueous).
Iron and steam.
Copper and HCI (aqueous).
Sodium and ethyl alcohol.
Cell reaction is spontaneous when.
Eored is negative.
Eored is positive
is negative
is positive
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.
Standard free energies of formation (in KJ/mol) at 298 K are -237.2, -394.4 and -8.2 for H2O(l) CO2(g) and pentane (g), respectively. The value of Eocell for the pentane-oxygen fuel cell is.
1.968 V
2.0968 V
1.0968 V
0.0968 V
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.
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
An electrochemical cell is shown below;
Pt,H2[1atm]/HCI (0.1M)//CH3COOH(0.1M)H2(1atm),Pt. The emf of the cell will not be zero, because
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.
