What is potential of platinum wire dipped into a solution of 0.1 M in Sn2+ and 0.01 M in Sn4+ ?
E°
E° + 0.059
E° +
E° - 0.059
Zn(s) | Zn2+(aq)|| Cu2+(aq) | Cu(s) is :
(anode) (cathode)
Weston cell
Daniel cell
Faraday cell
Standard cell
When 1 F of electricity is passed through acidulated water, O2 evolved is
11.2 dm3
5.6 dm3
22.4 dm3
1.0 dm3
The oxidation potential values of A, B, C and D are -0.03 V, +0.108 V, -0.07 V and +0.1 V respectively. The non-spontaneous cell reaction takes place between
A and B
Band D
D and A
B and C
Na is used in reduction of Zn salt because
E°Zn (oxi) > E°Na (oxi)
E°Zn (red) > E°Na (red)
E°Zn (oxi) < E°Na (oxi)
both (a) and (b)
C.
E°Zn (oxi) < E°Na (oxi)
Metals having higher oxidation potential (or lesser E°red) can replace metals having lesser oxidation potential.
Since, oxidation potential of Na is more than that of Zn. Therefore, Na is used to reduce Zn salts.
Reduction potentials of A, B, C and D are 0.8 V, 0.79 V, 0.34 V and -2.37 V respectively. Which element displaces all the other three elements?
B
A
D
C
During the electrolytic reduction of alumina, the reaction at cathode is
2H2O → O2 + 4H+ + 4e-
3F- → 3F + 3e-
Al3+ + 3e- → Al
2H+ + 2e- → H2
One ampere of current is passed for 9650 seconds through molten AlCl3. What is the weight in grams of Al deposited at cathode? (atomic weight of Al = 27)
0.9
9.0
0.09
90.0