MCQs for NCERT Class 12 Chemistry Chapter 3 Electrochemistry

Please refer to the MCQ Questions for Class 12 Chemistry Chapter 3 Electrochemistry with Answers. The following Electrochemistry Class 12 Chemistry MCQ Questions have been designed based on the latest syllabus and examination pattern for Class 12. Our experts have designed MCQ Questions for Class 12 Chemistry with Answers for all chapters in your NCERT Class 12 Chemistry book.

Electrochemistry Class 12 MCQ Questions with Answers

See below Electrochemistry Class 12 Chemistry MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O2 at STP will be
(a) 5.4 g
(b) 10.8 g
(c) 54.0 g
(d) 108.0 g 

Question. How many grams of cobalt metal will be deposited when a solution of cobalt(II) chloride is electrolyzed with a current of 10 amperes for 109 minutes?(1 Faraday = 96,500 C; Atomic mass of Co = 59 u)
(a) 4.0
(b) 20.0
(c) 40.0
(d) 0.66

Question. Al₂O₃ is reduced by electrolysis at low potentials and high currents. If 4.0 × 10⁴ amperes of current is passed through molten Al2O₃ for 6 hours, what mass of aluminium is produced? (Assume 100% current efficiency, at. mass of Al = 27 g mol^–1)
(a) 8.1 × 10⁴ g
(b) 2.4 × 10⁵ g
(c) 1.3 × 10⁴ g
(d) 9.0 × 10³ g 

Question. 4.5 g of aluminium (at. mass 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H+ ions in solution by the same quantity of electric charge will be
(a) 44.8 L
(b) 22.4 L
(c) 11.2 L
(d) 5.6 L 

Question. In electrolysis of NaCl when Pt electrode is taken then H2 is liberated at cathode while with Hg cathode it forms sodium amalgam. The reason for this is
(a) Hg is more inert than Pt
(b) more voltage is required to reduce H+ at Hg than at Pt
(c) Na is dissolved in Hg while it does not dissolve in Pt
(d) conc. of H+ ions is larger when Pt electrode is taken.

Question. A 5 ampere current is passed through a solution of zinc sulphate for 40 minutes. The amount of zinc deposited at the cathode is
(a) 0.4065 g
(b) 65.04 g
(c) 40.65 g
(d) 4.065 g 

Question. Sodium is made by the electrolysis of a molten mixture of about 40% NaCl and 60% CaCl2 because
(a) Ca++ can reduce NaCl to Na
(b) Ca++ can displace Na from NaCl
(c) CaCl₂ helps in conduction of electricity
(d) this mixture has a lower melting point than NaCl. 

Question. When CuSO₄ is electrolysed using platinum electrodes,
(a) copper is liberated at cathode, sulphur at anode
(b) copper is liberated at cathode, oxygen at anode
(c) sulphur is liberated at cathode, oxygen at anode
(d) oxygen is liberated at cathode, copper at anode.

Question. 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

Question. A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as
(a) dynamo
(b) Ni-Cd cell
(c) fuel cell
(d) electrolytic cell.

Question. The efficiency of a fuel cell is given by
(a) ΔG/DS
(b) ΔG/DH
(c) ΔS/DG
(d) ΔH/DG

Question. Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because
(a) zinc is lighter than iron
(b) zinc has lower melting point than iron
(c) zinc has lower negative electrode potential than iron
(d) zinc has higher negative electrode potential than iron. 

Question. The most convenient method to protect the bottom of ship made of iron is
(a) coating it with red lead oxide
(b) white tin plating
(c) connecting it with Mg block
(d) connecting it with Pb block. 

Question. To protect iron against corrosion, the most durable metal plating on it, is
(a) copper plating
(b) zinc plating
(c) nickel plating
(d) tin plating.

Question. Effect of dilution on conductivity of solution:
(a) Increases
(b) Decreases
(c) Unchanged
(d) None of the above

Question. Through a solution of CuSO₄ a current of 3 amperes was passed for 2 hours. At cathode 3 g of Cu²⁺ions were discharged. The current efficiency is [At. wt. of Cu = 63.5] 
(a) 33.3%
(b) 42.2%
(c) 48.7%
(d) 54.4%

Question. Which shows electrical conductance? 
(a) Sodium
(b) Diamond
(c) Potassium
(d) Graphite

Question. Which cannot displace hydrogen from its compound? 
(a) Al
(b) Fe
(c) Hg
(d) Pb

Question. For reducing one mole of Cr₂O₇^2- to Cr³⁺ the charge required is :
(a) 3 × 96500 coulomb
(b) 6 ×96500 coulomb
(c) 0.3 Faradays
(d) 0.6 Faradays

Question. Time required to deposit one millimole of aluminium metal by the passage of 9.65 amperes through aqueous solution of aluminium ion is
(a) 30 s
(b) 10 s 
(c) 30,000 s
(d) 10,000 s

Question. Which of the following statements is true for the electrochemical Daniel cell?
(a) Electrons flow from copper electrode to zinc electrode
(b) Current flows from zinc electrode to copper electrode
(c) Cations move toward copper electrode
(d) Cations move toward zinc electrode

Question. The charge required for the reduction of 1 mol of MnO^4- to MnO₂ is : 
(a) 1F
(b) 3 F
(c) 5F
(d) 6F

Question. The products formed when an aqueous solution of NaBr is electrolysed in a cell having inert electrodes are: 
(a) Na and Br₂
(b) Na and O₂
(c) H₂ ,Br₂ and NaOH
(d) H₂ and O₂

Question. The emf of Daniell cell at 298 K is E₁ Zn | ZnSO₄ (0.01 M) | | CuSO₄ (1.0 M) | Cu When the concentration of ZnSO₄ is 1.0 M and that of CuSO₄ is 0.01 M, the emf changed to E₂
What is the relation between E₁ and E₂?
(a) E₁ = E₂
(b) E₂ = 0 ≠ E₂
(c) E₁ > E₂
(d) E₁ < E₂

Question. Equivalent conductance of an electrolyte containing NaF at infinite dilution is 90.1 Ohm^–1cm₂. If NaF is replaced by KF what is the value of equivalent conductance?
(a) 90.1 Ohm^–1cm₂
(b) 111.2 Ohm^–1cm₂
(c) 0
(d) 222.4 Ohm^–1cm₂

Question. For a cell reaction involving two electron change, the standard EMF of the cell is 0.295 V at 2°C.
The equilibrium constant of the reaction at 25°C will be
(a) 29.5 × 10^–2
(b) 10
(c) 1 × 10¹⁰
(d) 2.95 × 10^–10

Question. A 0.5 M NaOH solution offers a resistance of 31.6 ohm in a conductivity cell at room temperature. What shall be the approximate molar conductance of this NaOH solution if cell constant of the cell is 0.367 cm^–1.
(a) 234 S cm₂ mole^–1
(b) 23.2 S cm₂ mole^–1
(c) 4645 S cm₂ mole^–1
(d) 5464 S cm₂ mole^–1

Question. The cell constant of a given cell is 0.47 cm^–1. The resistance of a solution placed in this cell is measured to be 31.6 ohm. The conductivity of the solution (in S cm^–1 where S has usual meaning) is 
(a) 0.15
(b) 1.5
(c) 0.015
(d) 150

Question. The standard reduction potentials at 298K for the following half reactions are given against each
Zn²⁺ (aq) + 2e ⇌ Zn(s) ; –0.762 V
Cr³⁺ (aq) + 3e ⇌ Cr (s); –0.740 V
2H+ (aq) + 2e ⇌ H2 (g) ; 0.00 V
Fe3+ (aq) + e ⇌ Fe²⁺ (aq) ;0.770 V
Which is the strongest reducing agent? 
(a) Zn (s)
(b) Cr (s)
(c) H2(g)
(d) Fe3+ (aq)

Question. Given that; Zn ²⁺ / Zn = – 0.762 V, 
Mg²⁺/Mg = – 2.37V Then, Zn + MgCI₂→ ?
(a) ZnCl₂ + Mg
(b) ZnCl₂ + MgCl₂
(c) Zn + Mg
(d) No reaction

Question. 1 M solution each of Cu(NO₃ )₂ , AgNO₃ , Hg₂(NO₃ )₂ and Mg(NO₃)₂ is electrolysed using Pt-electrodes. The values of standard electrode potentials in volts are
Ag⁺ / Ag = + 0.80 V, Cu²⁺/Cu = + 0.34 V,
Hg₂²⁺ /Hg = + 0.79V Mg²⁺ /Mg = – 2.37V
The sequence of deposition of metals on the cathode will be
(a) Mg, Ag, Cu
(b) Mg, Cu, Ag
(c) Ag, Hg, Cu
(d) Cu, Hg, Ag

Question. Consider the following cell reaction
2Fe(s)+ O₂ (g)+ 4H⁺ (aq) →
2Fe²⁺ (aq) + 2H₂O(/),E° = 1.67 V
At [Fe²⁺] = 10^-3 M, p_O2 = 0. 1 atrn and pH = 3, the cell potential at 25°C is 
(a) 1.47 V
(b) 1.77 V
(c) 1.87 V
(d) 1.57 V

Question. The reduction potential of hydrogen half-cell will negative if 
(a) p(H₂ ) = 1 atrn and [H⁺] = 2.0 M
(b) p(H₂ ) = 1 atm and [H⁺] = 1.0 M
(c) p(H₂ ) = 2atm and [H⁺] = 1.0 M
(d) p(H₂ ) = 2atrn and [H⁺] = 2.0 M

Question. E₁ , E₂ and E₃ are the emfs of the following three galvanic cells respectively
I. Zn(s) l Zn ²⁺ (0.1 M) ll Cu²⁺ (1 M) l Cu(s)
II. Zn(s) l Zn ²⁺ (1 M) ll Cu²⁺ (1 M) l Cu(s)
III. Zn(s) l Zn ²⁺ (1 M) ll Cu²⁺ (0.1 M) l Cu(s)
Which one of the following is true?
(a) E₂ > E₁ > E₃
(b) E₁ > E₂ > E₃
(c) E₃ > E₁ > E₂
(d) E₃ > E₂ > E₁

Question. The standard emf of a galvanic cell involving 2 moles of electrons in its redox reaction is 0.59 V. The equilibrium constant for the red ox reaction of the cell is
(a) 10²⁰
(b) 10⁵
(c) 10
(d) 10¹⁰

Question. The standard redox potentials for the reactions Mn ²⁺ + 2e^–→ Mn and Mn ³⁺ + e^–→ M²⁺ are – 1.18 V and 1.51 V respectively. What is the redox potential for the reaction Mn ³⁺ + 3e ^–→ Mn?
(a) 0.33 V
(b) 1.69 V
(c) – 0.28 V 
(d) – 0.85 V
(e) 0.85 V

Question. The standard reduction potential E° for half reactions are
Zn = Zn²⁺ + Ze,E° = + 0.76 V
Fe = Fe²⁺ + Ze, E° = + 0.41 V
The emf of the cell reaction
Fe²⁺ + Zn = Zn²⁺ + Fe is 
(a) – 0.35 V
(b) + 0.35 V
(c) + 1.17 V
(d) – 1.17 V

Question. Which of the following reactions is correct for a given electrochemical cell at 25°C?
Pt l Br₂(g) l Br^–(g ) ll Cl^–(aq) l Cl₂(g) l Pt 
(a) 2Br^– (aq)+ Cl₂ (g) → 2Cl^– (aq) + Br₂ (g)
(b) Br₂ (g)+ 2Cl^– (aq) → 2Br^– (aq) + Cl₂ (g)
(c) Br₂ (g)+ Cl₂ (g) → 2Br^– (aq) + 2Cl^– (aq)
(d) 2Br^– (aq) + 2Cl^– (aq) → Br₂ (g) + Cl₂ (g)

Question. In which of the following case, increase in concentration of ion cause increase in E_cell ? 
(a) Pt(H₂ ) l H⁺ (aq)
(b) Pt l Quinhydrone l H⁺ ( aq)
(c) Ag l Ag⁺ (aq)
(d) Ag, AgCI l Cl^–(aq)

Question. The standard emf of a cell involving one electron change is found to be 0.591 Vat 25°C. The equilibrium constant of the reaction is (F = 96500 C mol^-1)
(a) 1.0 x 10¹
(b) 1.0 x 10⁵
(c) 1.0 x 10¹⁰
(d) 1.0 x 10³⁰

Question. E° values of Mg²⁺ /Mg is – 2.37 V of Zn²⁺ /Zn is – 0.76 V and Fe²⁺ / Fe is – 0.44 V. Which of the statements is correct? 
(a) Zn will reduce Fe²⁺
(b) Zn will reduce Mg²⁺
(c) Mg oxidises Fe
(d) Zn oxidises Fe

Question. What will be the electrode potential of that hydrogen electrode is filled with HCl solution of pH value 1.0?
(a) – 59.15 V
(b) + 59.15 
(c) + 59.15 mV
(d) – 59.15 mV

Question. A hydrogen electrode is immersed in a solution with pH = 0 (HCl). By how much will the potential (reduction) change if an equivalent amount of NaOH is added to the solution.
(Take H2 p = 1 atm), T = 298 K. 
(a) increase by 0.41 V
(b) increase by 59 mV
(c) decrease by 0.41 V
(d) decrease by 59 mV

Question. Given that the standard reduction potentials for M+/M and N+/N electrodes at 298 K are 0.52 V and 0.25 V respectively. Which of the following is correct in respect of the following electrochemical cell ? M/M⁺ | | N⁺/N 
(a) The overall cell reaction is a spontaneous reaction.
(b) The standard EMF of the cell is – 0.27 V.
(c) The standard EMF of the cell is 0.77 V.
(d) The standard EMF of the cell is – 0.77 V.

Question. The specific conductance of a 0.1 N KCl solution at 23°C is 0.012 ohm^–1 cm^–1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be
(a) 0.918 cm^–1
(b) 0.66 cm^–1
(c) 1.142 cm^–1
(d) 1.12 cm^–1 

Question. On heating one end of a piece of a metal, the other end becomes hot because of
(a) energised electrons moving to the other end
(b) minor perturbation in the energy of atoms
(c) resistance of the metal
(d) mobility of atoms in the metal.

Question. A silver cup is plated with silver by passing 965 coulombs of electricity. The amount of Ag deposited is :
(a) 107.89 g
(b) 9.89 g
(c) 1.0002 g
(d) 1.08 g

Question.

Calculate Δ^∞ _HOAc using appropriate molar conductances of the electrolytes listed above at infinite dilution in H₂O at 25°C
(a) 217.5
(b) 390.7
(c) 552.7
(d) 517.2

Question. Kohlrausch’s law states that at
(a) finite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.
(b) infinite dilution each ion makes definite contribution to equivalent conductance of an electrolyte depending on the nature of the other ion of the electrolyte.
(c) infinite dilution, each ion makes definite contribution to conductance of an electrolyte whatever be the nature of the other ion of the electrolyte.
(d) infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.

Question. An electrolytic cell contains a solution of Ag₂SO₄ and has platinum electrodes. A current is passed until 1.6 gm of O₂ has been liberated at anode. The amount of silver deposited at cathode would be
(a) 107.88 gm
(b) 1.6 gm
(c) 0.8 gm
(d) 21.60 gm

Question. Limiting molar conductivity of NH₄OH     

Question. The volume of oxygen gas liberated at NTP by passing a current of 9650 coulombs through acidified water is
(a) 1.12 litre
(b) 2.24 litre
(c) 11.2 litre
(d) 22.4 litre

Question. At 25°C, the molar conductance at infinite dilution for the strong electrolytes NaOH, NaCl and BaCl₂ are 248 × 10^–4, 126 × 10^–4 and 280 × 10^–4 Sm²mol^–1 respectively. Λ⁰_m Ba(OH)₂ in S m² mol^–1 is
(a) 52.4 × 10^–4
(b) 524 × 10^–4
(c) 402 × 10^–4
(d) 262 × 10^–4

Question. To deposit one equivalent weight of silver at cathode, the charge required will be
(a) 9.65 × 10⁴ C
(b) 9.65 × 10³ C
(c) 9.65 × 10⁵ C
(d) 9.65 × 10⁷ C

Question. As lead storage battery is charged
(a) lead dioxide dissolves
(b) sulphuric acid is regenerated
(c) lead electrode becomes coated with lead sulphate
(d) the concentration of sulphuric acid decreases

Question. At 25°C molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is 9.54 ohm^-1 cm²mol^-1 and at infinite dilution its molar conductance is 238 ohm^-1 cm² mol^-1. The degree or ionisation of ammonium hydroxide at the same concentration and temperature is:
(a) 20.800%
(b) 4.008%
(c) 40.800%
(d) 2.080%

Question. ΛCICH₂COONa = 224 ohm^–1 cm² gmeq^–1 ,
NaCl 38.2 ohm^–1 cm² gmeq^–1 ,
HCl 203 ohm^–1 cm² gmeq^–1 , 
What is the value of  Λ_CICH2COOH 
(a) 288.5 ohm^–1cm²gmeq^–1
(b) 289.5 ohm^–1cm²gmeq^–1
(c) 388.8 ohm^–1cm²gmeq^–1
(d) 59.5 ohm^–1cm²gmeq

Question. The electrical properties and their respective SI units are given below. Identify the wrongly matched pair.
Electrical property                       SI unit
(a) Specific conductance                Sm^–1
(b) Conductance                           S
(c) Equivalent conductance            Sm² gequiv^–1
(d) Cell constant                          m

Question. Which of the following expressions correctly represents the equivalent conductance at infinite dilution of Al2(SO4)3,Given that ∧0Al3+  and ∧0 SO42– are the equivalent conductances at infinite dilution of the respective ions?   

Question. If 0.5 amp current is passed through acidified silver nitrate solution for 100 minutes. The mass of silver deposited on cathode, is (eq.wt.of silver nitrate = 108)
(a) 2.3523 g
(b) 3.3575 g
(c) 5.3578 g
(d) 6.3575 g

Question. Electrolysis of fused NaCl will give
(a) Na
(b) NaOH
(c) NaClO
(d) None of these

Question. Aluminium oxide may be electrolysed at 1000°C to furnish aluminium metal (At. Mass = 27 amu; 1 Faraday = 96,500 Coulombs). The cathode reaction is– Al³⁺ + 3e^– → Al
To prepare 5.12 kg of aluminium metal by this method we require electricity of
(a) 5.49 × 10¹ C
(b) 5.49 × 10⁴ C
(c) 1.83 × 10⁷ C
(d) 5.49 × 10⁷ C

Question. Which of the following is the use of electrolysis?
(a) Electrorefining
(b) Electroplating
(c) Both (a) & (b)
(d) None of these

Question. Which of the following batteries cannot be reused?
(a) Lead storage battery
(b) Ni-Cd cell
(c) Mercury cell
(d) Both (b) and (c)

Question. 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

Question. Find the charge in coulombs required to convert 0.2 mole VO₃ ^–2 into VO₄ ^–3 –
(a) 1.93 × 10⁴
(b) 9.65 × 10⁴
(c) 1.93 × 10⁵
(d) 9.65 × 10⁵

Question. The number of coulombs required to reduce 12.3 g of nitrobenzene to aniline is :
(a) 115800 C
(b) 5790 C
(c) 28950 C
(d) 57900 C

Question. On which of the following magnitude of conductivity does not depends?
(a) Nature of material
(b) Temperature
(c) Pressure
(d) Mass of the material

Question. The amount of electricity that can deposit 108 g of Ag from AgNO₃ solution is:
(a) 1 F
(b) 2 A
(c) 1 C
(d) 1 A

Question. Which colourless gas evolves, when NH₄Cl reacts with zinc in a dry cell battery
(a) NH₄
(b) N₂
(c) H₂
(d) Cl₂

Question. Which of the following expression correctly represents molar conductivity?
(a) ∧ _m K/C
(b) ∧ _m KA/l
(c)  ∧ _mKV
(d) All of these

Question. Molar ionic conductivities of a two-bivalent electrolytes x²⁺ and y^2- are 57 and 73 respectively. The molar conductivity of the solution formed by them will be
(a) 130 S cm² mol^–1
(b) 65 S cm² mol^–1
(c) 260 S cm² mol^–1
(d) 187 S cm² mol^–1

Question. On passing C ampere of electricity through a electrolyte solution for t second. m gram metal deposits on cathode.The equivalent weight E of the metal is

Question. Several blocks of magnesium are fixed to the bottom of a ship to
(a) make the ship lighter
(b) prevent action of water and salt
(c) prevent puncturing by under-sea rocks
(d) keep away the sharks

Question. The number of electrons passing per second through a cross-section of copper wire carrying 10–6 amperes of current per second is found to be
(a) 1.6 × 10^–19
(b) 6 × 10^–35
(c) 6 × 10^–16
(d) 6 × 10¹²

Question. The limiting molar conductivities of HCl, CH₃COONa and NaCl are respectively 425, 90 and 125 mho cm² mol^–1 at 25°C. The molar conductivity of 0.1 M CH₃COOH solutions is 7.8 mho cm² mol^–1 at the same temperature. The degree of dissociation of 0.1 M acetic acid solution at the same temperature is
(a) 0.10
(b) 0.02
(c) 0.15
(d) 0.03

Question. Cu⁺ (aq) is unstable in solution and undergoes simultaneous oxidation and reduction according to the reaction :
2Cu⁺ (aq)   ⇌  Cu²⁺ (aq) + Cu(s)
Choose correct Eº for given reaction if Eº Cu²⁺/Cu = 0.34 V and Eº Cu²⁺/Cu⁺ = 0.15 V
(a) –0.38 V
(b) +0.49 V
(c) +0.38 V
(d) –0.19 V

Question. In a cell that utilises the reaction

to cathode compartment, will
(a) increase the E and shift equilibrium to the right
(b) lower the E and shift equilibrium to the right
(c) lower the E and shift equlibrium to the left
(d) increase the E and shift equilibrium to the left

Question. For a cell reaction involving two electron change, the standard EMF of the cell is 0.295 V at 2°C. The equilibrium constant of the reaction at 25°C will be:
(a) 29.5 × 10^–2
(b) 10
(c) 1 × 10¹⁰
(d) 2.95 × 10^–10

Question. When a lead storage battery is discharged
(a) SO₂ is evolved
(b) Lead sulphate is consumed
(c) Lead is formed
(d) Sulphuric acid is consumed

Question. Standard cell voltage for the cell Pb | Pb²⁺ || Sn²⁺ | Sn is – 0.01 V. If the cell is to exhibit Ecell = 0, the value of [Sn²⁺] / [Pb²⁺] should be antilog of –
(a) + 0.3
(b) 0.5
(c) 1.5
(d) – 0.5

Question. The cell, Zn | Zn²⁺ (1M) ||Cu²⁺ (1M) | Cu (E⁰ cell 1.10 V
was allowed to be completely discharged at 298 K. The relative concentration of

(a) 9.65 × 10⁴
(b) antilog (24.08)
(c) 37.3
(d) 10^37.3.

Question. If the following half cells have E° values as   
A³⁺ + e– → A²⁺, E° = y₂V
A²⁺ + 2e– → A, E° = –y₁V
The E° of the half cell A³⁺ + 3e → A will be

Question. The oxidation potential of 0.05 M H₂SO₄ is
(a) –2 × 0.0591
(b) –0.01 × 0.0591
(c) –2.321 × 0.0591
(d) +1 × 0.0591

Question. For a relation
Δ_rG = -nFE_cell
Ecell = E⁰_cell in which of the following condition?
(a) Concentration of any one of the reacting species should be unity
(b) Concentration of all the product species should be unity.
(c) Concentration of all the reacting species should be unity.
(d) Concentration of all reacting and product species should be unity.

Question. The equivalent conductances of two strong electrolytes at infinite dilution in H₂O (where ions move freely through a solution) at 25°C are given below :

What additional information/ quantity one needs to calculate
Λ⁰ of an aqueous solution of acetic acid?
(a) Λ⁰ of chloroacetic acid (ClCH₂COOH)
(b) Λ⁰ of NaCl
(c) Λ⁰ of CH₃COOK
(d) the limiting equivalent coductance of H  ( λ⁰_H⁺ ) .

Question. Which of the following statements is incorrect regarding dry (Leclanche) cell?
(a) Cathode used in the cell is coated by powdered manganese dioxide and carbon.
(b) Most common application of this cell is in our transistors and clocks.
(c) At cathode, Mn is oxidised from + 3 to + 4.
(d) At anode Zn is oxidised from 0 to + 2.

Question. Resistance of 0.2 M solution of an electrolyte is 50 Ω. The specific conductance of the solution is 1.3 S m^–1. If resistance of the 0.4 M solution of the same electrolyte is 260 Ω, its molar conductivity is :
(a) 6.25 × 10^–4 S m² mol^–1
(b) 625 × 10^–4 S m² mol^–1
(c) 62.5 S m² mol^–1
(d) 6250 S m² mol^–1

Question. The most durable metal plating on iron to protect against corrosion is
(a) nickel plating
(b) copper plating
(c) tin plating
(d) zinc plating

Question. On passing a current of 1.0 ampere for 16 min and 5 sec through one litre solution of CuCl₂, all copper of the solution was deposited at cathode. The strength of CuCl₂ solution was (Molar mass of Cu= 63.5; Faraday constant = 96,500 Cmol^–1)
(a) 0.01 N
(b) 0.01 M
(c) 0.02 M
(d) 0.2 N

Question. Conductivity k, is equal to _________.

(a) (i) and (iii)
(b) (i) and (ii)
(c) (i), (ii) and (iii)
(d) (ii), (iii) and (iv)

Question. One Faraday of electricity is passed through molten Al₂O₃, aqueous solution of CuSO₄ and molten NaCl taken in three different electrolytic cells connected in series. The mole ratio of Al, Cu and Na deposited at the respective cathode
is
(a) 2 : 3 : 6
(b) 6 : 2 : 3
(c) 6 : 3 : 2
(d) 1 : 2 : 3

Question. Arrange the following in increasing order of their conductivity Na⁺ (A), K⁺ (B), Ca²⁺ (C), Mg²⁺(D)
(a) A, B, C, D
(b) B, A, C, D
(c) C, A, D, B
(d) A, B, D, C

Question. Consider the following four electrodes:
P = Cu²⁺ (0.0001 M)/Cu(s)
Q = Cu²⁺ (0.1 M)/Cu(s)
R = Cu²⁺ (0.01 M)/Cu(s)
S = Cu²⁺ (0.001 M)/Cu(s)
If the standard reduction potential of Cu²⁺/Cu is +0.34 V, the reduction potentials in volts of the above electrodes follow the order.
(a) P > S > R > Q
(b) S > R > Q > P
(c) R > S > Q > P
(d) Q > R > S > P

Question. The conductivity of electrolytic solutions depends upon which of the following?
(i) Size of ions produced
(ii) Viscosity of the solvent
(iii) Concentration of electrolyte
(iv) Solvation of ions produced
(a) (i) and (iii)
(b) (i), (ii) and (iii)
(c) (i), (iii) and (iv)
(d) All of these

Question. What is the potential of half-cell consisting of zinc electrode in 0.01 M ZnSO₄ solution at 25°C
(E⁰_ox = 0.763V)
(a) 0.8221 V
(b) 8.221 V
(c) 0.5282 V
(d) 9.282 V

Question. Mark the false statement?
(a) A salt bridge is used to eliminate liquid junction potential
(b) The Gibbs free energy change, ΔG is related with electromotive force E as ΔG = –nFE
(c) Nernst equation for single electrode potential is

(d) The efficiency of a hydrogen-oxygen fuel cell is 23%

Question. When electric current is passed through acidified water, 112 ml of hydrogen gas at STP collected at the cathode in 965 seconds. The current passed in amperes is
(a) 1.0
(b) 0.5
(c) 0.1
(d) 2.0

Question. At 298K the standard free energy of formation of H₂O (l) is –237.20 kJ/mole while that of its ionisation into H+ ion and hydroxyl ions is 80 kJ/mole, then the emf of the following
cell at 298 K will be [Take Faraday constant F = 96500C]
H₂ (g , 1 bar) | H⁺ (1M) | | OH^– (1M) | O₂(g, 1 bar)
(a) 0.40V
(b) 0.81V
(c) 1.23 V
(d) – 0.40 V

Question. In the electrolysis of water, one faraday of electrical energy would liberate
(a) one mole of oxygen
(b) one gram atom of oxygen
(c) 8 g oxygen
(d) 22.4 lit. of oxygen

Question. A weak electrolyte having the limiting equivalent conductance of 400 S cm². equivalent^–1 at 298 K is 2% ionized in its 0.1 N solution. The resistance of this solution
(in ohms) in an electrolytic cell of cell constant 0.4 cm^–1 at this temperature is
(a) 200
(b) 300
(c) 400
(d) 500

Question. Electrolysis of dilute aqueous NaCl solution was carried out by passing 10 milli ampere current. The time required to liberate 0.01 mol of H₂ gas at the cathode is (1 Faraday = 96500 C mol^–1)
(a) 9.65 × 10⁴ sec
(b) 19.3 × 10⁴ sec
(c) 28.95 × 10⁴ sec
(d) 38.6 × 10⁴ sec

Question. What is the amount of chlorine evolved when 2 amperes of current is passed for 30 minutes in an aqueous solution of NaCl ?
(a) 66 g
(b) 1.32 g
(c) 33 g
(d) 99 g

Question. 0.2964 g of copper was deposited on passage of a current of 0.5 amp for 30 mins through a solution of copper sulphate.Calculate the oxidation state of Cu (At. mass 63.56).
(a) +1
(b) +2
(c) +3
(d) +4

Question. What will happen during the electrolysis of aqueous solution of CuSO₄ by using platinum electrodes ?
(i) Copper will deposit at cathode.
(ii) Copper will deposit at anode.
(iii) Oxygen will be released at anode.
(iv) Copper will dissolve at anode.
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (i) and (ii)
(d) (ii) and (iii)

Question. On passing current through two cells, connected in series containing solution of AgNO₃ and CuSO₄, 0.18 g of Ag is deposited. The amount of the Cu deposited is:
(a) 0.529 g
(b) 10.623 g
(c) 0.0529 g
(d) 1.2708 g

Question. How much charge is required, when 1 mole of 2 Cr₂O₇^2- reduce to form 1 mole of Cr³⁺ ?
(a) 6F
(b) 3F
(c) 1F
(d) 2F

Question. A 0.5 M NaOH solution offers a resistance of 31.6 ohm in a conductivity cell at room temperature. What shall be the approximate molar conductance of this NaOH solution if
cell constant of the cell is 0.367 cm^–1.
(a) 234 S cm² mole^–1
(b) 23.2 S cm² mole^–1
(c) 4645 S cm² mole^–1
(d) 5464 S cm² mole^–1

Question. On electrolysis of dil. sulphuric acid using platinum (Pt) electrode, the product obtained at anode will be
(a) hydrogen gas
(b) oxygen gas
(c) H₂S gas
(d) SO₂ gas.