Three ampere currernt was passed through an aqueous solution of an unknown salt of Pd for 1 h 2.977 g of Pdn+ was deposited at cathode.The value of n is:
(given at wf of Pd= 106.4)
6
5
4
3
The metal which can displace all other metals from their salt solution among the following is:
Al
Zn
Cu
Fe
The standard reduction potentials of half reactions are given below:
F2 (g) + 2e- 2F- (aq) ; E0 = + 2.85 V
Cl2 (g) + 2e- 2Cl- (aq) ; E0 = + 1.36 V
Br2 (g) + 2e- 2Br- (aq) ; E0 = + 1.06 V
I2 (g) + 2e- 2I- (aq) ; E0 = + 0.53 V
The strongest oxidising and reducing agents respectively are:
chlorine and iodine
fluorine and iodine ion
chloride and bromine
bromine and iodine
Equivalent conductance of O .0128 N acetic acid solution, at 25°C is 14 ohm-1 eq-1 and at infinite dilution is 391 ohm-1eq-1 .The degree of dissociation of acetic acid in the solution and its dissociation constant, respectively are:
0.036 and 1.66x10-5
0.121 and 1.78x10-4
0 .213 and 1.84x10-5
O .054 and 1.94x10-4
Two metals 'A' and 'B' have E, value equal to 0.36 V and 1.23 V. What will be the correct cell equation?
A + B2+ A2+ + B
A2+ + B A + B2+
Both (a) and (b)
None of the above
Ag | AgCl | Cl- (C2) || Cl- (C1) | AgCl | Ag for this cell G is negative if:
C1 = C2
C1 > C2
C2 > C1
both (a) and (b)
Rusting of iron is a chemical reaction. The reaction is :
double decomposition
combination
displacement
analysis
Which one of the following conditions will increase the voltage of the cell represents by the equation?
Cu (s) + 2Ag+ (aq) Cu2+ (aq) + Ag (s)
Increase in the concentration of Ag+ ions
Increase in the concentration of Cu2+ ions
Increase in the dimensions of silver electrode
Increase in the dimensions of copper electrode
During the electrolysis of the aqueous solution of copper sulphate using Pt electrodes , the reaction taking place at the anode is:
Cu2+ + 2e- Cu
Cu Cu2+ + 2e-
2H2O 4H+ + O2 + 4e-
H2O + e- OH- + H2
Cadmium rods are used for which purpose?
emit electrons
absorb neutrons
emit neutrons
absorb electrons
B.
absorb neutrons
Cadmium rods are used to absorb neutrons in nuclear reactors, because cadmium is neutron absorber.