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Free download in PDF Class 12 Chemistry Chapter 3 Electrochemistry Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams like NEET, AIIMS, JIPMER etc. These short solved questions or quizzes are provided by Gkseries./p>
(1)
Molar conductivity of 0.15 M solution of KCl at 298 K, if its conductivity of 0.0152 S cm-1 w ill be
[A]
124 Ω-1 cm² mol-1
[B]
204 Ω-1 cm² mol-1
[C]
101 Ω-1 cm² mol-1
[D]
300 Ω-1 cm² mol-1
Answer: 101 Ω-1 cm² mol-1
(2)
Electrical conductance through metals is called metallic or electronic conductance and is due to the movement of electrons. The electronic conductance depends on
[A]
the nature and structure of the metal
[B]
the number of valence electrons per atom
[C]
change in temperature
[D]
all of these
(3)
The specific conductivity of N/10 KCl solution at 20°C is 0.0212 ohm-1 cm-1 and the resistance of the cell containing this solution at 20°C is 55 ohm. The cell constant is
[A]
3.324 cm-1
[B]
1.166 cm-1
[C]
2.372 cm-1
[D]
3.682 cm-1
(4)
Faraday’s law of electrolysis is related to
[A]
Atomic number of cation
[B]
Speed of cation
[C]
Speed of anion
[D]
Equivalent weight of electrolyte
Answer: Equivalent weight of electrolyte
(5)
The molar conductivity is maximum for the solution of concentration
[A]
0.004 M
[B]
0.002 M
[C]
0.005 M
[D]
0.001 M
(6)
Units of the properties measured are given below. Which of the properties has been not matched correctly?
[A]
Molar conductance = Sm2 mol-1
[B]
Cell constant = m-1
[C]
Specific conductance of = S m²
[D]
Equivalence conductance = S m² (g eq)-1
Answer: Specific conductance of = S m²
(7)
How long would it take to deposit 50 g of Al from an electrolytic cell containing Al2O3 using a current of 105 ampere?
[A]
1.54 h
[B]
1.42 h
[C]
1.32 h
[D]
2.15 h
(8)
How much electricity in in terms of Faraday is required to produce 100 g of Ca from molten CaCl2?
[A]
1F
[B]
2F
[C]
3F
[D]
5F
(9)
How much time is required to deposit 1 × 10-3 cm thick layer of silver (density of 1.05 g cm-3) on a surface of area 100 cm² by passing a current of 5 A through AgNO3 solution?
[A]
125 s
[B]
115 s
[C]
18.7 s
[D]
27.25 s
(10)
The aqueous solution of which of the following compounds is the best conductor of electric current?
[A]
Acetic acid
[B]
Hydrochloric acid
[C]
Ammonia
[D]
Fructose
Answer: Hydrochloric acid
(11)
An increase in the conductivity equivalent of a solid electrolyte with dilution is primarily due to
[A]
increased ionic mobility of ions
[B]
100 percent electrolyte ionisation with natural dilution
[C]
increase in both ion numbers and ionic mobility
[D]
a rise in ion counts
Answer: increased ionic mobility of ions
(12)
The ionic conductance of Ba2+ and Cl– are respectively 127 and 76 ohm-1 at infinite dilution. The equivalent conductance of BaCl2 at infinite dilution will be
[A]
139.5
[B]
203
[C]
279
[D]
101.5
(13)
When heating one end of a metal plate, the other end gets hot because of
[A]
the resistance of the metal
[B]
mobility of atoms in the metal
[C]
energised electrons moving to the other end
[D]
minor perturbation in the energy of atoms
Answer: energised electrons moving to the other end
(14)
The weight of silver displaced by a quantity of electricity which displaces 5600ml of O2 at STP will be
[A]
5.4g
[B]
10.8g
[C]
54.9g
[D]
108.0g
(15)
Once a current of 1.0 ampere was passed through one litre of CuCl2 solution for 16 min and 5 sec, all of the solution’s copper was deposited at the cathode. The power of solution CuCl2 was (Molar mass of Cu = 63.5; Faraday constant = 96,500 C/mol)
[A]
0.01N
[B]
0.01M
[C]
0.02M
[D]
0.2N
(16)
On electrolysis of dilute sulphuric acid using platinum electrodes, the product obtained at the anode will be
[A]
hydrogen
[B]
oxygen
[C]
hydrogen sulphide
[D]
sulphur dioxide
(17)
A device that converts the energy of combustion of fields like hydrogen and methane directly into electrical energy is known as
[A]
Electrolytic cell
[B]
Dynamo
[C]
Ni-Cd cell
[D]
Fuel cell
(18)
Which reaction is not feasible?
[A]
2KO + Br2 2KBr + I2
[B]
2KBr + I2 2KI + Br2
[C]
2KBr + Cl2 2KCl + Br2
[D]
2H2O + 2F2 4HF + O2
Answer: 2KBr + I2 2KI + Br2
(19)
Without losing its concentration ZnCl2 solution cannot be kept in contact with
[A]
Au
[B]
Al
[C]
Pb
[D]
Ag
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