E1, E2, E3 are the emf values of the three galvanic cells respectively.
Which one of the following is true?
E1> E2 >E3
E2 >E3 >E1
E3 >E2 > E1
E1> E3 >E2
Which one of the following has a potential more than zero?
Pt, H2 (1 atm) | HCl (2M)
Pt, H2 (1 atm) | HCl (0.1 M)
Pt, H2 (1 atm) | HCl (0.5 M)
Pt, H2 (1 atm) | HCl (1M)
100 mL of 0.1 M acetic acid is completely neutralized using a standard solution of NaOH. The volume of ethane obtained at STP after the complete electrolysis of the resulting solution is
56 mL
224 mL
560 mL
112 mL
The emf of a galvanic cell constituted with the electrode Zn2+|Zn (-0.76V) and Fe2+|Fe (-0.41V) is
-0.35V
+ 1.17V
+0.35V
-1.17V
For hydrogen-oxygen fuel cell at 1 atm and 298 K
H2 (g) + O2 (g) → H2O (l) ; G° = -240 kJ
E° for the cell is approximately, (Given F = 96500 C)
2.48 V
1.25 V
2.5 V
1.26 V
While charging the lead storage battery,
PbSO4 on anode is reduced to Pb
PbSO4 on cathode is reduced to Pb
PbSO4 on cathode is oxidised to Pb
PbSO4 on anode is oxidised to PbO2
A.
PbSO4 on anode is reduced to Pb
The cell reactions during charging of lead storage battery are
At anode : PbSO4(s) + 2e- → Pb(s) + SO (aq)
At cathode: PbSO4(s) + 2H2O (l) → PbO2 (s) + SO(aq)+ 4H+(aq)+ 2e-.
So, PbSO4 at anode is reduced to Pb.
In H2-O2 fuel cell the reaction occurring at cathode is
2H2 (g) + O2 → 2H2O(l)
O2(g) + 2H2O(l) + 4e- → 4OH-(aq)
H+ +e- → 1/2H2
H+(aq) + OH- → H2O(l)
Which of the following is incorrect in a galvanic cell?
Oxidation occurs at anode
Reduction occurs at cathode
The electrode at which electrons are gained is called cathode
The electrode at which electrons are lost is called cathode
A secondary cell is one
can be recharged
can be recharged by passing current through it in the same direction
can be recharged by passing current through it in the opposite direction
cannot be recharged
The amount of current in Faraday, is required for the reduction of 1 mole of Cr2O ions to Cr3+ is
1 F
2 F
6 F
4 F