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Free download in PDF Class 12 Chemistry Chapter 3 Electrochemistry Multiple Choice Questions (MCQs) 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)
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 strength 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
(2)
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
(3)
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
(4)
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
(5)
Without losing its concentration ZnCl2 solution cannot be kept in contact with
[A]
Au
[B]
Al
[C]
Pb
[D]
Ag
(6)
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
(7)
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
(8)
The equivalent conductance of Ba2+ and Cl– are respectively 127 and 76 ohm-1 cm-1 eq-1 at infinite dilution. The equivalent conductance of BaCl2 at infinite dilution will be
[A]
139.5
[B]
203
[C]
279
[D]
101.5
(9)
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
(10)
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
(11)
A new galvanic cell of E^u more than E°dl of Daniel cell is connected to Daniel cell in a manner that new cell gives electrons to cathode, what will happen
[A]
Ecell will increase
[B]
Ecell will decrease
[C]
No change will take place
[D]
Daniel cell will work as electrolytic cell where Zn will be deposite on zinc rod and copper will dissolve from copper rod.
Answer: Daniel cell will work as electrolytic cell where Zn will be deposite on zinc rod and copper will dissolve from copper rod.
(12)
Ag+(aq) + e– → Ag(s) E° = + 0.80 V
Fe2+(aq)+ + 2e– → Fe(s) E° = – 0.44 V
What is emf of
Fe(s) + 2Ag+(aq) → Fe2+(aq) + 2Ag(s)
[A]
1.16 V
[B]
1.24 V
[C]
2.04 V
[D]
-1.16 V
(13)
A conductivity cell containing electrodes made up of
[A]
Gold
[B]
Silver
[C]
Platinised platinum
[D]
Copper
Answer: Platinised platinum
(14)
The standard emf of a galvanic cell involving cell reaction with n = 2 is formed to be 0.295 V at 25° C. The equilibrium constant of the reaction would be
[A]
1.0 × 1010
[B]
2.0 × 1011
[C]
4.0 × 1012
[D]
1.0 × 102
(15)
Which of the following statement is correct?
[A]
ECell and ∆rG of cell reaction both are extensive properties.
[B]
ECell and ∆rG of cell reaction both are . intensive properties.
[C]
ECell is an intensive property while ∆rG of cell reaction is an extensive property.
[D]
ECell is an extensive property while ∆rG of cell reaction is an intensive property.
Answer: ECell is an intensive property while ∆rG of cell reaction is an extensive property.
(16)
While charging the lead storage battery _________
[A]
PbSO4 anode is reduced to Pb
[B]
PbSO4 cathode is reduced to Pb
[C]
PbSO4 cathode is oxidised to Pb
[D]
PbSO4 anode is oxidised to PbO2
Answer: PbSO4 anode is reduced to Pb
(17)
Λ of M/32 solution of weak acid is 8 S cm2 mol-1 and limiting molar conductivity is 400 S cm2 mol1. Ka for acid is
[A]
1.25 × 10-6
[B]
6.25× 10-4
[C]
1.25 × 10-4
[D]
1.25 × 10-5
(18)
The positive value of the standard electrode potential of Cu2+/Cu indicates that _________
[A]
this redox couple is a stronger reducing agent than the H+/H2 couple
[B]
this redox couple is a stronger oxidising agent than H+/H2
[C]
Cu can displace H2 from acid
[D]
Cu cannot displace H2 from acid
Answer: this redox couple is a stronger oxidising agent than H+/H2
(19)
The charge required for the reduction of 1 mol of MnO2– to MnO2 is
[A]
1 F
[B]
3 F
[C]
5 F
[D]
6 F
(20)
If limiting molar conductivity of Ca2+ and Cl– are 119.0 and 76.3 S cm2 mol-1, then the value of limiting molar conductivity of CaCl2 will be
[A]
195.3 S cm2 mol-1
[B]
271.6 S cm2 mol-1
[C]
43.3 S cm2 mol-1
[D]
314.3 S cm2 mol-1
Answer: 271.6 S cm2 mol-1
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