Cu+ (aq) is unstable in solution and undergoes simultaneous oxidation and reduction according to the reaction
- 0.38 V
+ 0.49 V
+ 0.38 V
- 0.19 V
Standard reduction potentials at 25oC of Li+ / Li, Ba2+ / Ba, Na+ / Na and Mg2+ / Mg are -3.05, -2.90, -2.71 and -2.37 volt respectively. Which one of the following is the strongest oxidising agent?
Mg2+
Ba2+
Na+
Li+
Reduction potential for the following half-cell reactions are
+ 0.32 V
- 0.32 V
+ 1.20 V
- 1.20 V
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
The efficiency of a fuel cell is given by
ΔG / ΔS
ΔG / ΔH
ΔS / ΔG
ΔH / ΔG
Cell reaction is spontaneous when
Eored is negative
Eored is positive
ΔGo is negative
ΔGo is positive
Without losing its concentration ZnCl2 solution cannot be kept in contact with
Au
Al
Pb
Ag
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
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
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)