Equivalent conductance of NaCl, HCl and C2H5COONa at infinite 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 efficiency of a fuel cell is given by
ΔG / ΔS
ΔG / ΔH
ΔS / ΔG
ΔH / ΔG
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
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
On the basis of the following Eo Values, the strongest oxidising agent is
[Fe(CN)6]4-
Fe2+
Fe3+
[Fe(CN)6]3-
For the cell reaction,
Cu2+ (C1, aq) + Zn (s) Zn2+ (C2, aq) + Cu (s) of an electrochemical cell, the change in free energy (ΔG) at a given temperature is a function of
In (C1)
In (C2/ C1)
In (C2)
In (C1 + C2)
Cell reaction is spontaneous when
Eored is negative
Eored is positive
ΔGo is negative
ΔGo is positive
In electrolysis of NaCl 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 dissolve in Pt
Concentration of H+ ions is larger when Pt electrode is taken
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
Cu+ (aq) is unstable in solution and undergoes simultaneous oxidation and reduction according to the reaction
2 Cu+ (aq) Cu2+ (aq) + Cu (s)
Choose the correct Eo for above reaction if
- 0.38 V
+ 0.49 V
+ 0.38 V
- 0.19 V
