CBSE
The specific conductance of a N/ 10 KCl at 25°C is 0.0112 ohm-1cm-1.The resistance of cell containing solution at the same temperature was found to be 55 ohm. The cell constant will be
6.16 cm-1
0.616 cm-1
0.0616 cm-1
616 cm-1
If hydrogen electrode dipped in two-solution of pH = 3 and pH = 6 and salt bridge is connected , the emf of resulting cell is :
0.177 V
0.3 V
0.052 V
0.104 V
If the Zn2+/Zn electrode is diluted to 100 times then the change in emf :
increase of 59 mV
decrease of 59 mV
increase of 29.5 mV
decrease of 29.5 mV
During electrolysis of water the volume of oxygen liberated is 2.24 dm3 .The volume of hydrogen liberated , under same conditions will be :
2.24 dm3
1.12 dm3
4.48 dm3
0.56 dm3
Ni/Ni2+ [1.0 M] || Au3+ [1.0 M]/Au (where E° for Ni2+/Ni is -0.25 V E° for Au3+/Au is 0.150 V)
Whar is the emf of the cell ?
+ 0.4 V
- 1.75 V
+ 1.25 V
+ 1.75 V
In acidic medium MnO42- is converted to Mn2+ .The quantity of electricity in faraday required to reduce 0.5 mole of MnO42- to Mn2+ would be :
2.5
1
5
0.5
The time period to coat a metal surface of 80 cm2 with 5 x 10-3 cm thick layer of silver (density 1.05 g cm-3) with the passage of 3 A current through a silver nitrate solution is
115 sec
125 sec
135 sec
145 sec
For the following concentration cell, to be spontaneous Pt(H2)P1 atm. |HCl | Pt(H2)P2 atm. Which of the following is correct?
P1=P2
P1<P2
P1>P2
Can't be predicted
In a lead storage battery , reaction at cathode is :
Pb + SO42- PbSO4 + 2e-
Pb + PbO2 + 2H2SO4 2PbSO4 + 2H2O
PbSO4 + 2e- Pb + SO42-
PbO2 + 4H+ + SO42- + 2e- PbSO4 + 2H2O
If equivalent conductance of 1 M benzoic acid is 12.8 ohm-1 cm and if the conductance of benzoate ion and H+ ion are 42 and 288 .42 ohm-1 cm2 respectively .Its degree of dissociation is :
39 %
3.9 %
0.35 %
0.039 %