ELECTROCHEMISTRY MCQs

By: Prof. Dr. Fazal Rehman | Last updated: February 3, 2024

ELECTROCHEMISTRY MCQs

Which relation corresponds to Faradays’ law of electrolysis?

1. ΔF = -nFE°
2. E = mc²
3. E = hu
4. m = Zt

m = Zt

Electrochemistry

---

Which statement is not true with reference to cell constant?

1. The dimensions of cell constant is cm
2. Specific conductance does not vary with concentration
3. It is measured with KCl solution
4. It is helpful and used to determine the specific conductance

Specific conductance does not vary with concentration

---

Which solids is a better ‘conductor of electricity?

1. Pure NaCl crystals
2. Sulfur
3. Diamond
4. Graphite

Graphite

---

____ is the device that converts the energy of fuel directly into electrical energy.

1. Galvanic cell
2. Electrolytic
3. Concentration cell
4. Fuel cell

Fuel cell

---

When some quantity of electricity is passed through two electrolytic cells, the ratio of the mass of the products obtained at the cathode is the same as the ratio of their

1. Equivalent masses
2. Atomic masses
3. Densities
4. Atomic numbers

Equivalent masses

---

The blue color of CuSO, disappears on adding Zn granules to it. It is because of

1. Oxidation of Cu atom
2. Oxidation of Zn²⁺
3. Reduction of Zn²⁺
4. Reduction of Cu^{2 +}

Reduction of Cu²⁺

---

Which statement is not true with reference to ionic conductors?

1. Ionic conductance is due to movement of the ions
2. It decreases with rise in temperature
3. It involves oxidation reduction reaction
4. It involves the of matter

It decreases with rise in temperature

---

---

The unit of specific conductance will be

1. Mho cm
2. Ohm cm
3. Ohm cm^-1
4. S cm^-1

S cm^-1

---

The conductance of 1 cm³ of an electrolyte solution is called its

1. Specific resistance
2. Molar conductance
3. Specific conductance
4. Equivalent conductance

Specific conductance

---

---

Which ion has high mobility in aqueous solution?

1. K⁺
2. Al⁺⁺⁺
3. Ca⁺⁺
4. H⁺

H⁺

---

---

Which solutions of NaCl will have the highest specific conductance?

1. 0.001 N
2. 0.01 N
3. 1.0 N
4. 0.1 N

1.0 N

---

Electrolytic conduction is due to the movement of which of the following?

1. Electrons
2. Molecules
3. Atoms
4. Ions

Ions

---

Which statement is not true with reference to Arrhenius theory of electrolytic dissociation?

1. Electrolytes dissociate into charged species called ions in aqueous solution
2. The ions are not free to move
3. The extent of dissociation also depends on the temperature of the electrolyte
4. The extent of dissociation depends on the concentration of the electrolyte

The ions are not free to move

---

The branch of chemistry which is concerned with the interrelation of electrical and chemical energy is called

1. Reaction dynamics
2. Electrochemistry
3. Surface chemistry
4. Kinetics

---

Equivalent conductance is expressed in the units

1. S cm² eq^–¹
2. S cm eq^–¹
3. S cm² eq^–¹
4. S cm^–¹ eq^–¹

S cm² eq^–¹

---

The fraction of the total current carried by an ion is called its ____.

1. Transport number
2. Ionic mobility
3. Limiting ionic conductance
4. None of A, B, and C

Transport number

---

---

If for a solution of an electrolyte, t₄ is the transport number of the cation, then what is will be the transport number of the anion t?

1. t₊/2
2. 1 + t₊
3. 1 – t₊
4. (1 – t)/2

1 + t₊

---

Which process forever involve an increase in oxidation number?

1. Oxidation
2. Decomposition
3. Reduction
4. Hydrolysis

Oxidation

---

Which statement is true?

1. The transport number of a cation is equal to its equivalent conductance
2. The transport number of an ion is inversely proportional to its mobility
3. The sum of the transport numbers of all the ions present is a solution in unity
4. The transport number of a cation is equal to that of the anion

The sum of the transport numbers of all the ions present is a solution in unity

---

---

In which compounds the oxidation numberr of Cl is +3?

1. CIF₃
2. CIO₃
3. ICI
4. HCIO₄

CIF₃

---

What happens during a reaction of copper with aqueous solution of silver nitrate?

1. Silver atoms are reduced
2. Cu ions are reduced
3. Nitrate ions are reduced
4. Silver ions are reduced

Silver ions are reduced

---

What is the unit for the cell constant?

1. Ώ^-1 cm^-1
2. cm²
3. cm^-1
4. cm^-3

cm^-1

---

During the titration of weak acid against NaOH, the conductance of the solution after the neutralization point

1. Is constant
2. Increases
3. Varies irregularly
4. Decreases

Increases

---

According to the Debye-Huckel theory of strong electrolytes, an ion moving in an atmosphere of oppositely charged ions experiences a drag. This effect is called _____ .

1. Concentration effect
2. Electrophoretic effect
3. Inter-ionic effect
4. Asymmetric effect

Asymmetric effect

---

Which procedure permanently causes the oxidation number to decrease?

1. Reduction
2. Hydrolysis
3. Oxidation
4. Decomposition

Reduction

---

What is the oxidation number of I in HIO₄?

1. +7
2. +3
3. +5
4. +6

+7

---

Which reaction is not a redox reaction?

1. Na₂O+ H₂SO4 → Na₂SO4 + H₂O
2. 2Na + O₂ → Na₂O₂
3. SO₂+2H₂S → 2H₂O + S
4. NO+ 2H₂S → 2HO + N

Na₂O+ H₂SO4 → Na₂SO4 + H₂O

---

What is the oxidation number of Mn in KMnO₄?

1. +5
2. -7
3. +7
4. +3

+7

---

Which specie is the strongest oxidizing agent in their standard state?

1. Cl^–
2. Fe²⁺
3. Cu²⁺
4. Co³⁺

Co³⁺

---

Which statement is not true with respect to electrolytic conductors?

1. New products are shown at the electrodes
2. A single stream of electrons flow from cathode to anode
3. Positive temperature coefficient is observed for the conductance
4. Ions are responsible to carry current

A single stream of electrons flow from cathode to anode

---

Which electrodes have E°_red = 0?

1. Cl₂/Ag⁺, Aq)
2. Cl₂/Cl^–, Pt
3. H₂/2H⁺, Pt
4. Cu²⁺/Cu

H₂/2H⁺, Pt

---

The species undergoing reduction in following reaction is Cr + 2H₂O + C10 → Cr³⁺ +3Cl¯ +6OH¯

1. CIO
2. H₂O
3. Cr
4. CIT

CIO

---

Which is a cathodic reaction?

1. Fe²⁺ → Fe²⁺
2. ₂2H₂O → 2OH + H2
3. 4OH → 2H₂O + O
4. 2SO₄^2- → SO₈^2-

2H₂O → 2OH + H2

---

From the of activity series, the ideal reducing agent among the following is?

1. I^– ions
2. CI^– ions
3. Br^– ions
4. F^– ions

I^– ions

---

In the cell reaction Cu + 2Ag⁺ → Cu²⁺ + 2Ag the reduction half reaction is +2Ag(s)

1. Cu – 2e → Cu
2. 2Ag + 2e → 2Ag
3. 2Ag → 2Ag⁺ + 2e
4. Cu²⁺ + 2e → Cu

Cu²⁺ + 2e → Cu

---

The electrode Pt/Fe²⁺(C₁), Fe³⁺(C₂) belongs to the type

1. Gas electrodes
2. Metal-metal insoluble salt electrode
3. Amalgam electrodes
4. Inert metal electrodes

Inert metal electrodes

---

According to the latest convention, the e.m.f. of a cell may be expressed in terms of the reduction potentials RHS electrode (E_R) and LHS electrode (E_L) as

1. E_cell = E_L – E_R
2. E_cell = E_R/E_L
3. E_cell = E_R + E_L
4. E_cell = E_R – E_L

E_cell = E_R – E_L

---

Oxidation number of S in H₂SO₄ is

1. +8
2. +4
3. +6
4. +2

+4

---

Which statement is not true regarding galvanic cells?

1. Oxidation occurs at the anode
2. Ions carry current inside the cell
3. When the e.m.t. of the cell is positive cell reaction is spontaneous
4. Electrons flow around the external circuit, from cathode to anode

Electrons flow around the external circuit, from cathode to anode

---

The mathematical equation E – E°= -RT/nF In Q where Q is the reaction quotient is called

1. Nernst equation
2. Free energy equation
3. Helmholtz equation
4. Newton’s equation

Nernst equation

---

The emf of the cell Zn Zn2+ || Ag|Ag is independent of

1. Temperature
2. The molarity of Zn ions in the solution
3. The molarity of Ag+ ions in the solution
4. The volume of Zn2+ and Ag+ solutions

The volume of Zn2+ and Ag+ solutions

---

For Which cells, the standard voltage is zero

1. Daniel cell
2. Fuel cell
3. Electrolytic cell
4. Concentration cell

Concentration cell

---

Cell potential depends on which of the following?

1. Temperature
2. Concentration of ions
3. Nature of electrolyte
4. All of A, B, and C

All of A, B, and C

---

The depolarizer helpful and used in dry cell batteries is

1. NH₄CI
2. Na₃PO₄
3. KOH

D MnO₂

MnO₂

---

In lead storage battery, the anode reaction is

1. Pb²⁺ + 2e → Pb
2. None of A, B, and C
3. PbO + H₂SO₄ → PbSo₄ + H2O
4. Pb + H₂SO₄ → PbS0₄ + 2H⁺ + 2e^–

Pb + H₂SO₄ → PbS0₄ + 2H⁺ + 2e^–

---

The cell in which a non-spontaneous redox reaction takes place as a result of electricity is know as

1. Voltaic cell
2. Dry cell
3. Daniel cell
4. Electrolytic cell

Electrolytic cell

---

The process of burning of hydrogen in an environment of oxygen to form water can be described as

1. Oxidation only
2. Reduction only
3. Hydrogenation of oxygen
4. Redox reaction

Redox reaction

---

Reaction taking place at anode in galvanic cells is

1. Reduction
2. Oxidation
3. Hydrolysis
4. Ionization

Oxidation

---

A half-cell reaction is one that

1. Forever oxidizes
2. Goes only half way to completion
3. Involves a half mole of the concentration of the solution
4. Occurs at one electrode

Occurs at one electrode

---

The oxidation state of carbon in sucrose is

1. Zero
2. +3
3. -4
4. +4

Zero

---

Which metals cannot displace copper from copper sulfate solution?

1. Magnesium
2. Aluminum
3. Sodium
4. Iron

Iron

---

Concentration polarization arises because of the

1. Different concentrations of solutions in the two half cells
2. Variation in temperature during measurements
3. Reversible nature of the cell
4. Changes in the concentration of electrolyte around the electrode from bulk concentration

Changes in the concentration of electrolyte around the electrode from bulk concentration

---

In a standard Weston cell, the cathode is

1. Cadmium amalgam
2. Carbon
3. Platinum
4. Mercury

Mercury

---

Overall positive value of cell potential predicts that the process is

1. Feasible
2. Reversible
3. Impossible
4. Not feasible

Feasible

---

Which is a primary cell?

1. Fuel cell
2. Alkaline dry cell
3. Daniel cell
4. Lead accumulator

Alkaline dry cell

---

In superoxide, the oxidation number of oxygen is

1. -1/2
2. -1
3. +1
4. Zero

-1/2

---

In which compound the oxidation state of Cl is +5

1. NaCl
2. HOCI
3. NaClO₄
4. NaClO₃

NaClO₃

---

When brine solution is electrolyzed Which ions get discharged at anode?

1. Na⁺
2. OH^–
3. H⁺
4. CI^–

CI^–

---

Which is not reduction?

1. Gain of electron
2. Decrease in negative oxidation state
3. Loss of oxygen
4. Gain of hydrogen

Gain of hydrogen

---

In silver oxide battery anode is made up of which of the following?

1. NiO₂
2. Cd.
3. Ag₂O
4. Zn

Zn

---

In an electrolytic cell

1. Electrical energy is converted into heat
2. Electrical energy is converted into mechanical energy
3. Electrical energy is converted into chemical energy
4. Chemical energy is converted into electrical energy

Electrical energy is converted into chemical energy

---

When a lead storage battery is discharged

1. Sulfuric acid is consumed
2. Lead sulfate is consumed
3. SO₂ is evolved
4. Lead is formed

Sulfuric acid is consumed

---

Faraday’s laws of electrolysis are related to

1. Equivalent mass of the electrolyte
2. Atomic number of anion
3. Atomic number of the cation
4. Speed of the cation

Equivalent mass of the electrolyte

---

When copper wire is placed in a solution of silver nitrate. The solution acquires a blue color. This is due to the formation of

1. Cu⁺ ions
2. Soluble complex of copper with silver nitrate
3. Cu²⁺ ions
4. Reduction of copper

Cu²⁺ ions

---

The electric charge for electrode depositio of one gram equivalent of a substance is

1. One ampere per second
2. 96500 coulombs per second
3. One ampere per hour
4. Charge on one mole of electrons

Charge on one mole of electrons

---

The reaction taking place in fuel cell is

1. 2H₂ + 4OH → 4H₂O (l) +4e
2. O₂ – 2H₂O +4e^– → 4OH^–
3. Both A & B
4. None of A, B, and C

Both A & B

---

Which is true for an electrochemical cell?

1. H₂ is anode and Cu is cathode
2. Reduction occurs at the H₂-electrode
3. Oxidation occurs at Cu electrode
4. H₂ is cathode and Cu is anode

H₂ is anode and Cu is cathode

---

A cell reaction is spontaneous if the cell potential is

1. Positive
2. Zero
3. Negative
4. Infinite

Positive

---

Identify the true statement regarding fuel cells.

1. They are more efficient
2. They are free from pollution
3. They run till the reactants are active
4. All of A, B, and C

All of A, B, and C

---

In Which the free energy of a chemical reaction is directly converted to electricity?

1. Lead storage battery
2. Lechlanche cell
3. Concentration cells
4. Fuel cells

Fuel cells

---

In a galvanic cell

1. Chemical energy is converted into heat
2. Electrical energy is converted into heat
3. Chemical energy is converted into electrical energy
4. Electrical energy is converted into chemical energy

Electrical energy is converted into chemical energy

---

Which has same oxidation state in all of its compounds?

1. Be
2. Cl
3. P
4. N

Be

More Physical Chemistry MCQs

1. PHYSICAL CHEMISTRY MCQs
2. CHEMICAL AND IONIC EQUILIBRIA MCQs
3. NUCLEAR CHEMISTRY MCQs
4. CHEMICAL THERMODYNAMICS MCQs
5. NANOCHEMISTRY MCQs
6. CHEMICAL KINETICS MCQs
7. SURFACE CHEMISTRY MCQs
8. COLLOIDAL STATE MCQs
9. ELECTROCHEMISTRY MCQs
10. SPECTROSCOPY MCQs
11. SOLUTION CHEMISTRY AND PHASE EQUILIBRIA MCQs
12. PHOTOCHEMISTRY AND MOLECULAR SYMMETRY MCQs
13. CHEMISTRY MCQs From all subjects of  Chemistry

---