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
At 298K the standard free energy of formation of H2O(l) is –237.20kJ/mole while that of its ionisation into H+ iion and hydroxyl ions is 80 kJ/mole, then the emf of the following cell at 298 K will be
H2(g,1 bar) | H+ (1M) || OH–(1M) | O2 (g, 1bar)
(1) 0.40 V
(2) 0.81 V
(3) 1.23 V
(4) –0.40 V
Which of the following cell can produce more electric work.
(1) pt,H2|NH4Cl||0.1MCH3COOH|H2,pt
(2) pt,H2|0.1MHCl||0.1MNaOH|H2,pt
(3) pt,H2|0.1MHCl||0.1MCH3COOK|H2,pt
(4) pt,H2|0.1MCH3COOK||0.1MHCl|H2,pt
At what does the following cell have its reaction at equilibrium?
Ag(s) | Ag2CO3(s) | Na2CO3 (aq) || KBr(aq) | AgBr(s) | Ag(s)
KSP = 8 × 10–12 for Ag2CO3 and KSP = 4 × 10–13 for AgBr
(1) × 10–7
(2) × 10–7
(3) × 10–7
(4) × 10–7