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
H2O2 is
a catalyst
an oxidising agent
a reducing agent
both '2' and '3'
The standard reduction potentials of Zn and Ag in water are Zn+2 + 2e- Zn ;(Eo = -0.76 V) and Ag+ + e- Ag; (Eo = + 0.80 V) at 298 K. Which of the following reaction is feasible?
Zn(s) + 2Ag+(aq) → Zn+2(aq) + 2Ag(s)
Zn+2(aq) + Ag+(aq) → Zn(s) + Ag(s)
Zn(s) + Ag(s) → Zn+2(aq) + Ag+(aq)
Zn+2(aq) + 2Ag(s)→2Ag+(aq) + Zn(s)
The amount of mercury deposited by passing 300 C of charge through mercurous sulphate solution is (Take atomic weight of mercury as 200)
0.2 g
0.4 g
0.6 g
0.8 g
The charge of one electron is (Avogadro's number = 6.023 × 1023)
1 × 10-19 C
1.6 × 10-19 C
2.6 × 10-19 C
3.6 × 10-19 C
The standard e.m.f of a galvanic cell, with standard electrode potentials of zinc equal to -0.76 V and that of copper equal to + 0.34 V, is
+ 0.76 V
+ 1.1 V
- 0.34 V
- 1.1 V
The e.m.f of a galvanic cell with electrode potentials of silver equal to + 0.80 V and that of copper equal to + 0.34 V is
-0.46 V
-1.14 V
+0.46 V
+ 1.14 V
The oxidation state of Cr in [Cr(NH3)4Cl2]+ is
+ 3
+ 2
+ 1
0
If emf of the cell Zn| Zn2 (0.01 M)| | Fe2+ (0.001 M) | Fe at 298 K is 0.2957, then the value of equilibrium constant for the cell reaction is?
Which of the following transition metal shows highest oxidation state?
Sc
Ti
Os
Zn
