Redox Reactions: Master the Basics with Engaging Quizzes

Question 1

Explain the function of a salt bridge in an electrochemical cell.

Accepted Answer

Allows ion flow

Answer

Prevents solution mixing

Answer

Generates potential difference

Answer

Acts as a catalyst

Question 2

In the electrochemical cell: Zn | Zn2+(1 M) || Cu2+(1 M) | Cu, identify the cathode.

Accepted Answer

Cu electrode

Answer

Zn electrode

Answer

Salt bridge

Answer

Voltmeter

Question 3

In the reaction: Fe + 2HCl → FeCl₂ + H₂, which species is the oxidizing agent?

Accepted Answer

HCl

Answer

Fe

Answer

FeCl₂

Answer

H₂

Question 4

Identify the reaction that is a disproportionation reaction:

Accepted Answer

2Fe²⁺ → Fe + Fe³⁺

Answer

MnO₄⁻ + 8H⁺ + 5e⁻ → Mn²⁺ + 4H₂O

Answer

2Cu²⁺ + 4I⁻ → 2CuI + I₂

Answer

H₂ + Cl₂ → 2HCl

Question 5

Which of the following is the half-reaction for the reduction of copper ions?

Accepted Answer

Cu²⁺ + 2e⁻ → Cu

Answer

Cu → Cu²⁺ + 2e⁻

Answer

2Cu²⁺ + 4e⁻ → 2Cu

Answer

Cu + 2e⁻ → Cu²⁺

Question 6

Define oxidation in terms of electron transfer.

Accepted Answer

Loss of electrons

Answer

Gain of electrons

Answer

Gain of protons

Answer

Loss of protons

Question 7

In the reaction: Fe + CuSO₄ → FeSO₄ + Cu, which species undergoes reduction?

Accepted Answer

Cu

Answer

Fe

Answer

Both Fe and Cu

Answer

Neither Fe nor Cu

Question 8

What is the oxidation state of manganese in MnO₂?

Accepted Answer

+6

Answer

+2

Answer

+4

Answer

-2

Question 9

What is the primary purpose of a salt bridge in an electrochemical cell?

Accepted Answer

To maintain electrical neutrality in the solutions

Answer

To allow electrons to flow between electrodes

Answer

To prevent mixing of the solutions

Answer

To amplify the voltage of the cell

Question 10

Which of the following factors does not affect the EMF of an electrochemical cell?

Accepted Answer

Strength of the magnetic field

Answer

Concentration of reactants

Answer

Temperature

Answer

Size of the electrodes

Question 11

What is the standard hydrogen electrode (SHE) primarily used for?

Accepted Answer

As a reference electrode

Answer

To generate hydrogen gas

Answer

To measure the pH of a solution

Answer

To amplify the voltage of an electrochemical cell

Question 12

Which of the following species acts as a reducing agent?

Accepted Answer

H₂O₂

Answer

Fe³⁺

Answer

Cl₂

Answer

Cr₂O₇²⁻

Question 13

Which defining feature characterizes redox reactions?

Accepted Answer

Electron transfer between species

Answer

Electron loss always lowers oxidation state

Answer

Exclusively occur in acidic environments

Answer

Prohibit the formation of new chemical bonds

Question 14

In the reaction: Fe + CuSO₄ → FeSO₄ + Cu, which species is the oxidizing agent?

Accepted Answer

CuSO₄

Answer

Fe

Answer

FeSO₄

Answer

Cu

Question 15

What is the oxidation state of nitrogen in HNO₃?

Accepted Answer

+5

Answer

+1

Answer

+3

Answer

-3

Question 16

What is the balanced equation for the electrolysis of water?

Accepted Answer

2H₂O → 2H₂ + O₂

Answer

H₂O → 2H + O

Answer

2H₂O → 4H + O₂

Answer

H₂O → H₂ + O⁻₂

Question 17

Redox reactions involve the transfer of electrons. Which of the following processes describes a redox reaction?

Accepted Answer

The electrolysis of water

Answer

The combustion of methane

Answer

The reaction of an acid with a base

Answer

The melting of ice

Question 18

In the compound HCl, the oxidation state of chlorine is:

Accepted Answer

-1

Answer

+1

Answer

0

Answer

+5

Question 19

The standard electrode potential of the Standard Hydrogen Electrode (SHE) is:

Accepted Answer

0 V

Answer

1 V

Answer

-1 V

Answer

2 V

Question 20

Lead-acid batteries are an example of which type of electrochemical cell?

Accepted Answer

Galvanic cell

Answer

Electrolytic cell

Answer

Fuel cell

Answer

Solar cell

Question 21

In an alkaline solution, the half-reaction for the reduction of oxygen is:

Accepted Answer

O2 + 2H2O + 4e- → 4OH-

Answer

O2 + 4H+ + 4e- → 2H2O

Answer

O2 + 2H+ + 2e- → H2O2

Answer

O2 + H2O + 2e- → HO2-

Question 22

Which of the following elements is the strongest reducing agent?

Accepted Answer

Li

Answer

Fe

Answer

Cu

Answer

Au

Question 23

The Faraday constant represents:

Accepted Answer

The charge of one mole of electrons

Answer

The number of electrons in one mole of a substance

Answer

The rate at which electrons are transferred

Answer

The potential difference between two electrodes

Question 24

Which of the following is the correct order of the alkali metals in terms of their increasing oxidizing power?

Accepted Answer

Li < Na < K < Rb < Cs

Answer

Cs < Rb < K < Na < Li

Answer

Na < K < Rb < Cs < Li

Answer

K < Rb < Cs < Li < Na

Question 25

In the reaction: Fe + Cu2+ → Fe2+ + Cu, which species undergoes oxidation?

Accepted Answer

Fe

Answer

Fe2+

Answer

Cu2+

Answer

Cu

Question 26

What is the standard reduction potential of the standard hydrogen electrode?

Accepted Answer

0.00 V

Answer

1.00 V

Answer

-1.00 V

Question 27

Determine the oxidation state of nitrogen in the nitrate ion (NO3-)

Accepted Answer

+5

Answer

+3

Answer

-3

Question 28

Which of the following reactions is an example of a disproportionation reaction?

Accepted Answer

2Cu+ → Cu + Cu2+

Answer

Fe + 2HCl → FeCl2 + H2

Answer

H2 + Cl2 → 2HCl

Answer

2Na + Cl2 → 2NaCl

Question 29

What is the primary function of a salt bridge in an electrochemical cell?

Accepted Answer

To maintain electrical neutrality

Answer

To allow electrons to flow

Answer

To act as a catalyst

Answer

To prevent the mixing of solutions

Question 30

Write the balanced half-reaction equation for the reduction of Fe3+ to Fe2+.

Accepted Answer

Fe3+ + e- → Fe2+

Answer

Fe2+ → Fe3+ + e-

Answer

Fe2+ + e- → Fe3+

Answer

Fe3+ → Fe2+ + e-

Question 31

In the reaction 2Fe + 3Cl2 → 2FeCl3, which species undergoes oxidation?

Accepted Answer

Fe

Answer

Cl

Answer

FeCl3

Answer

Neither Fe nor Cl

Question 32

Which of the following reactions is classified as a redox reaction?

Accepted Answer

Zn + 2HCl → ZnCl2 + H2

Answer

NH3 + HCl → NH4Cl

Answer

2NaHCO3 → Na2CO3 + H2O + CO2

Answer

NaOH + HCl → NaCl + H2O

Question 33

In the reaction Cu + 2AgNO3 → Cu(NO3)2 + 2Ag, which substance acts as the oxidizing agent?

Accepted Answer

AgNO3

Answer

Cu(NO3)2

Answer

Ag

Answer

Cu

Question 34

The electrolysis of water results in the formation of which gases?

Accepted Answer

Hydrogen and Oxygen

Answer

Oxygen and Chlorine

Answer

Hydrogen and Chlorine

Question 35

What is the primary function of a salt bridge in an electrochemical cell?

Accepted Answer

To maintain electrical neutrality

Answer

To allow the flow of electrons

Answer

To increase the voltage of the cell

Answer

To separate the solutions