The weight of silver (atomic weight = 108) displaced by a quantity of electricity which displaces 5600 mL of O2 at STP will be :
1. 5.4 g
2. 10.8 g
3. 54.0 g
4. 108.0 g
At 25° C molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is
9.54 ohm1cm2mol-1 and at infinite dilution its molar conductance is 238 ohm1cm2mol-1.
The degree of ionisation of ammonium hydroxide at the same concentration and
temperature is
1. 2.080%
2. 20.800%
3. 4.008%
4. 40.800%
A button cell used in watches functions as following
Zn(s) + Ag2O(s) + H2O (l) 2Ag(s) + Zn2+(aq) + 2OH-(aq)
If half cell potentials are
The cell potential will be
1. 0.84 V
2. 1.34 V
3. 1.10 V
4. 0.42 V
Limiting molar conductivity of NH4OH (i.e Åm(NH4OH)) is equal to:-
1. Åm (NH4Cl)+Åm(NaCl)-Åm(NaOH)
2. Åm(NaOH)+Åm(NaCl)-Åm(NH4Cl)
3. Åm(NH4OH)+Åm(NH4Cl)-Åm(HCl)
4. Å(NH4Cl)+Å(NaOH)-Å(NaCl)
Kohlrausch's law states that at
(1) finite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.
(2) infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte depending on the nature of the other ion of th electrolyte.
(3) infinite dilution, each ion makes definite contribution to conductance of an electrolyte whatever be the nature of the other ion of the electrolyte.
(4) 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 E°cell for the pentane-oxygen fuel cell is
(1) 1.968 V
(2) 2.0968 V
(3) 1.0968 V
(4) 0.0968 V
The equilibrium constant of the reaction:
Cu (s) + 2Ag+ (aq) Cu2+ (aq) + 2Ag(s) ;
Eo = 0.46 V at 298 K is:
1. | 2.4 x 1010 | 2. | 2.0 x 1010 |
3. | 4.0 x 1010 | 4. | 4.0 x 1015 |
A hypothetical electrochemical cell is shown below A l A+ (xM)l l B+ (yM) l B
The Emf measured is +0.20 V.The cell reaction is:-
(1) A+ + B → A + B+
(2) A+ + e- → A ; B+ + e- → B
(3) the cell reaction cannot be predicted
(4) A + B+ → A+ + B
The E° in the given diagram is,
(1) 0.5
(2) 0.6
(3) 0.7
(4) 0.8