The e.m.f. of a cell prepared by combining Al/Al+3 and Ag/Ag+ is 2.46 V. The reduction potential of the silver electrode is + 0.80 V. The reduction potential of the aluminium electrode is
+ 1.66 V
- 3.26 V
+ 3.26 V
- 1.66 V
The oxidation number of oxygen atom in O22- ion is
- 1
-2
-3
-5
An electrochemical cell reaction is : Pt, H2 (1 atm) | HCl(0.1 M) | |CH3COOH (0.1 M) | H2(1 atm), Pt. The e.m.f of this cell will not be zero, because
temperature is constant
e.m.f depends upon molarities of acids used
acids used in two compartments are different
pH of 0.1 M HCl and 0.1 M CH3COOH is not same
Same amount of electric current is passed through solutions of AgNO3 and HCl. If 1.08 g of silver is obtained in the first case, the volume of hydrogen liberated at S.T.P in the second case is?
22400 ml
2240 ml
224 ml
112 ml
The electrode potentials of half-cell reactions are: Zn → Zn2+ + 2e- ; E = -0.76 V and Fe → Fe2+ + 2e- ;E = 0.41 V. The e.m.f of cell Fe2+ + Zn →Zn2+ + Fe is
+ 1.17 V
- 1.17 V
- 0.35 V
For standard reduction potentials of three metals A, B and C are +0.5 V, -3.0 V and -1.2 V respectively. The reducing powers of these metals are
B > C > A
A > B > C
C > B > A
A > C > B
A Daniell cell is represented as Zn(s) + Cu2+(aq) →ºCu(s) + Zn2+(aq). The value of standard free energy change in the cell is (Eºcell = 1.1V),
300 kJ
-300 kJ
212.3 kJ
-212.3 kJ
In the cell reaction Zn | Zn2+ (1M) II CO3+ (1M) | CO2+ (1M), the value of Eocell is (EoZn2+|Zn = -0.76, Eo CO3+|CO3+ = 1.82 V)
2.58 V
3.58 V
4.58 V
5.58 V
The oxidation number of nitrogen in (N2H5)+ is
+ 3
+ 2
In which of the following reaction, ozone acts as a reductant?
Ag2O + O3 → 2Ag + 2O2
KNO2 + O3 → KNO3 + O2
PbS + 4O3 → PbSO4 + 4O2
Na3AO3 + O3 → Na3AsO4 + O2
