Electrochemistry Test 1

intro

Quiz System

Enter time in seconds:

Time left: 30:00

MCQ 1:

What do we add to balance a chemical equation through the ion-electron method in basic media?

A) Twice the amount of Nitrogen atoms
B) Twice the amount of OH^– ions
C) Twice the amount of H₂SO₄ ions
D) An equivalent number of H⁺ ions

Topic: Balancing of Chemical Equations in Basic Media

Correct Answer: B) Twice the amount of OH^– ions

Detailed Hint:

The process of balancing chemical equations involves equalizing the number of each atom type on both sides of the equation.
In the ion-electron method in basic media, to balance oxygen atoms, two times the number of hydroxide ions (OH^–) are added because each hydroxide ion contains one oxygen atom.
So, the correct response is B, "Twice the amount of OH^– ions".

MCQ 2:

At which part does reduction occur during electrolysis?

A) Anode
B) Cathode
C) Both anode and cathode
D) Depending on the type of electrode material

Topic: Electrolysis and Reduction Process

Correct Answer: B) Cathode

Detailed Hint:

Electrolysis involves the breaking down of substances through electric current, and reduction occurs at the cathode.
Reduction is the gain of electrons, and the cathode in an electrolysis setup is the site where electrons are available.
So, the right answer is B, "Cathode".

MCQ 3:

What happens if a strip of copper metal is put into a solution of FeSO₄?

A) Copper will be precipitated.
B) Iron is precipitated.
C) Both Copper and Iron dissolve.
D) No reaction occurs.

Topic: Chemical Reactions in Electrochemical Series

Correct Answer: D) No reaction occurs.

Detailed Hint:

In the electrochemical series, copper is below Fe⁺².
This means that copper cannot displace iron from its compound, in this case, FeSO₄.
Therefore, the correct answer is D, "No reaction occurs".

MCQ 4:

What does an oxidizing agent do during a redox reaction?

A) Gains electrons
B) Loses electrons
C) Gets hydrolyzed
D) None of the above

Topic: Oxidation-Reduction (Redox) Reactions

Correct Answer: A) Gains electrons

Detailed Hint:

In redox reactions, there is a transfer of electrons between substances.
The oxidizing agent gains electrons, undergoing reduction in the process, while causing the other substance to be oxidized.
So, the correct answer is A, "Gains electrons".

MCQ 5:

What happens to the voltage between two half cells if a salt bridge is not used?

A) Decreases rapidly.
B) Decreases slowly.
C) Remains unchanged.
D) Drops to zero.

Topic: Role of Salt Bridge in Electrochemical Cells

Correct Answer: D) Drops to zero.

Detailed Hint:

A salt bridge plays a vital role in electrochemical cells, facilitating ionic current flow between the two half cells.
When a salt bridge is not used, the ionic current stops, which in turn halts the flow of the electronic current.
As a result, the voltage between the half cells falls to zero, making D the correct answer.

MCQ 6:

What is the relation between the strength of an oxidizing agent and the following attributes:

A) Oxidation potential
B) Reduction potential
C) Redox potential
D) Electromotive force (EMF) of the cell

Topic: Relationship between Oxidizing Agent Strength and Reduction Potential

Correct Answer: B) Reduction potential

Detailed Hint:

An oxidizing agent's strength is closely linked to reduction potential in electrochemical reactions.
A strong oxidizing agent has a high reduction potential value, indicating its likelihood to undergo a reduction reaction.
So, the correct answer is B, "Reduction potential".

MCQ 7:

Why don't metals like copper, silver, gold, and platinum liberate hydrogen gas when they react with acids?

A) These metals have very low ionization potentials.
B) Their reduction potentials are negative.
C) They have very high negative values of reduction potentials and lie above the standard hydrogen electrode (SHE).
D) They have very high positive values of reduction potentials.

Topic: Metal Reactivity and Reduction Potentials

Correct Answer: D) They have very high positive values of reduction potentials.

Detailed Hint:

Metals like Copper, Silver, Gold, and Platinum do not liberate hydrogen gas when they react with acids due to their positions on the electrochemical series.
These metals have high positive reduction potential values, and they do not readily oxidize or reduce H+ ions from acids.
So, the correct answer is D, "They have very high positive values of reduction potentials".

MCQ 8:

Identify the best conductor of electricity from the following options:

A) Pure distilled water.
B) Chloroform.
C) Dilute solution of glucose.
D) Molten NaCl.

Topic: Conductivity of Different Materials

Correct Answer: D) Molten NaCl.

Detailed Hint:

The conductivity of a substance is largely determined by the presence of charge carriers such as ions.
Pure distilled water and chloroform are poor conductors as they lack free ions.
A dilute solution of glucose, though it contains ions, is not as efficient a conductor as molten NaCl, which in its molten state releases a large number of ions that facilitate electrical conduction.
Hence, the correct answer is D, "Molten NaCl".

MCQ 9:

The electrochemical series provides insight into:

A) Large positive standard reduction potentials indicating strong oxidizing agents.
B) Small positive standard reduction potentials indicating strong oxidizing agents.
C) Large positive standard oxidation potentials indicating strong oxidizing agents.
D) Small positive standard oxidation potentials indicating strong oxidizing agents.

Topic: Significance of Electrochemical Series

Correct Answer: A) Large positive standard reduction potentials indicating strong oxidizing agents.

Detailed Hint:

The electrochemical series is a tool that helps us understand the behavior of various elements in redox reactions.
Strong oxidizing agents typically display large positive standard reduction potentials. This is because a high reduction potential indicates a strong tendency for the substance to be reduced, a characteristic of a strong oxidizing agent.
Therefore, the correct answer is A, "Large positive standard reduction potentials indicating strong oxidizing agents".

MCQ 10:

When the electrolysis of an aqueous solution of NaCl is conducted using a graphite electrode, which substance is collected at the cathode?

A) Hydrogen gas.
B) Sodium metal.
C) Sodium hydroxide.
D) Chlorine gas.

Topic: Electrolysis and Product Collection

Correct Answer: A) Hydrogen gas.

Detailed Hint:

During electrolysis, different substances are produced at the cathode and anode depending on the solution and the electrode used.
In the electrolysis of an aqueous solution of NaCl using a graphite electrode, hydrogen gas is released at the cathode. This is because the reduction of water is energetically more feasible than the reduction of Na+.
Consequently, the correct answer is A, "Hydrogen gas".

MCQ 11:

What is the highest reduction potential in the electrochemical series and its associated value?

A) F₂, +1.49 V.
B) F₂, +2.78 V.
C) F₂, +2.87 V.
D) F₂, -3.87 V.

Topic: Electrochemical Series and Reduction Potentials

Correct Answer: C) F₂, +2.87 V.

Detailed Hint:

The electrochemical series offers insight into the reduction potentials of different elements.
In this series, fluorine (F₂) has the highest reduction potential with a value of +2.87 V.
Therefore, the correct answer is C, "F₂, +2.87 V".

MCQ 12:

What is the oxidation number of a free element?

A) 0.
B) 1.
C) 2.
D) -1.

Topic: Oxidation States of Free Elements

Correct Answer: A) 0.

Detailed Hint:

The oxidation number is a concept in chemistry that helps in understanding the distribution of electrons in a chemical reaction.
For free (uncombined) elements, the oxidation number is always taken to be zero.
Therefore, the correct answer is A, "0".

MCQ 13:

Which ion undergoes reduction during the electrolysis of molten NaCl?

A) Cl^-.
B) Na⁺.
C) Either Na⁺ or Cl^-.
D) Both Na⁺ and Cl^-.

Topic: Electrolysis and Ion Reduction

Correct Answer: B) Na⁺.

Detailed Hint:

During electrolysis, either oxidation or reduction occurs, depending on whether the substance is at the anode or the cathode.
In the case of molten NaCl, Na⁺ ions are reduced to form sodium metal, which is collected at the cathode.
Therefore, the correct answer is B, "Na⁺".

MCQ 14:

What are the applications of the electrochemical series?

A) Predicting the feasibility of a chemical reaction.
B) Comparing the tendency of metals to undergo oxidation or reduction.
C) Calculating the voltage of a reaction.
D) All of the above.

Topic: Applications of Electrochemical Series

Correct Answer: D) All of the above.

Detailed Hint:

The electrochemical series is a crucial tool in understanding various aspects of chemical reactions.
It allows us to predict the feasibility of a reaction, compare which metals are most likely to get oxidized or reduced, and calculate the voltage of a reaction.
Therefore, the correct answer is D, "All of the above".

Question 15:

On what factor does the oxidizing power of an element depend?

A) Oxidation potential.
B) Ionization energy.
C) Electron affinity.
D) Electrode potential.

Topic: Factors Affecting Oxidizing Power

Correct Answer: D) Electrode potential.

Detailed Hint:

The oxidizing power of an element refers to its ability to attract and accept electrons.
It largely depends on the electrode potential of the element - a measure of its capacity to gain or lose electrons.
Therefore, the correct answer is D, "Electrode potential".

Question 16:

In the electrolysis of aqueous CuCl2, what metal is deposited at the cathode?

A) Sodium.
B) Aluminum.
C) Copper.
D) Lead.

Topic: Metal Deposition in Electrolysis

Correct Answer: C) Copper.

Detailed Hint:

During electrolysis, the metal ion in the solution gets reduced at the cathode and is deposited as a metal.
In the case of aqueous CuCl2, Cu2+ ions are reduced, resulting in the deposition of copper metal at the cathode.
Therefore, the correct answer is C, "Copper".

Question 17:

Which statement accurately describes the properties of a Standard Hydrogen Electrode (SHE)?

A) Its oxidation potential is zero, but its reduction potential is positive.
B) Its reduction potential is zero, but its oxidation potential is negative.
C) Both its oxidation potential and reduction potential are zero.
D) The solution in the electrode is 0.1 molar HCl.

Topic: Properties of Standard Hydrogen Electrode

Correct Answer: C) Both its oxidation potential and reduction potential are zero.

Detailed Hint:

The Standard Hydrogen Electrode (SHE) serves as a reference for measuring electrode potentials of half-cells.
By convention, both the oxidation potential and reduction potential of SHE are considered to be zero.
Therefore, the correct answer is C, "Both its oxidation potential and reduction potential are zero".

Question 18:

What is the role of a salt bridge in an electrolytic cell?

A) To pass the electric current.
B) To prevent the flow of ions.
C) To mix solutions of two half cells.
D) To allow movement of ions between two cells.

Topic: Function of Salt Bridge in Electrolytic Cells

Correct Answer: D) To allow movement of ions between two cells.

Detailed Hint:

A salt bridge is a critical component of an electrolytic cell, linking the two half-cells.
Its main function is to maintain electrical neutrality by allowing the transfer of ions between the two cells.
Therefore, the correct answer is D, "To allow movement of ions between two cells".

Question 19:

Which of the following is the best reducing agent?

A) F^-
B) Cl^-
C) Br^-
D) I^-

Topic: Determining the Best Reducing Agent

Correct Answer: D) I^-

Detailed Hint:

A reducing agent is a substance that loses or "donates" electrons in a chemical reaction, thereby reducing another substance.
Among the options provided, iodine ion (I^-) is the best reducing agent because of its largest size and the least effective nuclear charge, which make it easier to lose an electron.
Therefore, the correct answer is D, "I^-".

Question 20:

Given that the reduction potential of Aluminum (Al) is -1.66V and of Tin (Sn) is -0.14V, can you identify which of these two electrodes would act as the cathode when they are connected through a salt bridge?

A) An Aluminum (Al) electrode.
B) A Tin (Sn) electrode.
C) It depends on the cell's temperature.
D) It depends on the concentration of the solution in the salt bridge.

Topic: Identification of Cathode in Electrolysis

Correct Answer: B) A Tin (Sn) electrode.

Detailed Hint:

In an electrochemical cell, the electrode with the higher (less negative) reduction potential generally acts as the cathode.
Given the reduction potential values, Tin (Sn) has a higher reduction potential (-0.14V) than Aluminum (Al) (-1.66V).
Therefore, the correct answer is B, "A Tin (Sn) electrode".

Question 21:

Can you determine the correct order of increasing stability for the +1 oxidation state among these elements: Aluminum (Al), Gallium (Ga), Indium (In), Thallium (Tl)?

A) Ga < In < Al < Tl.
B) Al < Ga < In < Tl.
C) Tl < In < Ga < Al.
D) In < Tl < Ga < Al.

Topic: Oxidation State Stability Sequence

Correct Answer: C) Tl < In < Ga < Al.

Detailed Hint:

As we move down a group in the periodic table, the stability of the lower oxidation state tends to increase - this is primarily due to the inert pair effect.
Considering this trend, the stability of the +1 oxidation state increases in the sequence Tl < In < Ga < Al.
Therefore, the correct answer is C, "Tl < In < Ga < Al".

MCQ 22:

What is the fixed potential value for a Standard Hydrogen Electrode?

A) 0 V.
B) 1.0 V.
C) 0.1 V.
D) 0.001 V.

Topic: Potential of Standard Hydrogen Electrode

Correct Answer: A) 0 V.

Detailed Hint:

The Standard Hydrogen Electrode (SHE) is used as a reference point in measuring electrode potentials.
By convention, its potential is fixed and defined as 0 V.
Therefore, the correct answer is A, "0 V".

MCQ 23:

What is the oxidation state of Chlorine (Cl) in Magnesium Chloride (MgCl₂)?

A) +2.
B) -2.
C) -1.
D) 0.

Topic: Determining Oxidation State in a Compound

Correct Answer: C) -1.

Detailed Hint:

In a compound, the total oxidation state is always equal to zero.
Considering the oxidation state of Magnesium (Mg) is +2, for the compound MgCl₂ to equal zero, Chlorine (Cl) must have an oxidation state of -1.
Therefore, the correct answer is C, "-1".

MCQ 24:

Could you identify the oxidation state of Chlorine in Magnesium Chloride (MgCl₂)?

A) +2.
B) -2.
C) -1.
D) 0.

Topic: Oxidation State in a Chemical Compound

Correct Answer: C) -1.

Detailed Hint:

The total oxidation states in a compound should always add up to zero.
Given that Magnesium (Mg) has an oxidation state of +2, for the compound to balance out, Chlorine (Cl) must have an oxidation state of -1.
Therefore, the correct answer is C, "-1".

MCQ 25:

Which of the following is an example of a redox reaction?

A) NaCl + AgNO₃ → NaNO₃ + AgCl₂.
B) 2Na + Cl₂ → 2NaCl.
C) 2Cl → Cl₂ + 2e^–.
D) Na⁺ + 1e^– → Na.

Topic: Identification of Redox Reactions

Correct Answer: B) 2Na + Cl₂ → 2NaCl.

Detailed Hint:

A redox reaction is a type of chemical reaction where the oxidation states of atoms are changed. It involves both reduction (gain of electrons) and oxidation (loss of electrons).
In option B, Sodium (Na) is oxidized (loses an electron) and becomes Na⁺, and Chlorine (Cl₂) is reduced (gains an electron) and becomes 2Cl^–.
Therefore, the correct answer is B, "2Na + Cl₂ → 2NaCl".

MCQ 26:

In the following chemical reaction, what happens to Iron (Fe)?

2Fe + 3Cl₂ → 2FeCl₃

A) Fe undergoes reduction.
B) Fe undergoes oxidation.
C) Chlorine (Cl₂) undergoes oxidation.
D) None of the above.

Topic: Oxidation in a Chemical Reaction

Correct Answer: B) Fe undergoes oxidation.

Detailed Hint:

Oxidation refers to the loss of electrons during a chemical reaction.
In the given reaction, Iron (Fe) changes to Fe⁺³, signifying the loss of electrons.
Therefore, the correct answer is B, "Fe undergoes oxidation".

MCQ 27:

How would you define a cathode?

A) An electrode where reduction takes place and electrons are gained.
B) An electrode where oxidation occurs and electrons are lost.
C) A substance that conducts electricity.
D) None of the above.

Topic: Definition of a Cathode

Correct Answer: A) An electrode where reduction takes place and electrons are gained.

Detailed Hint:

In electrochemistry, a cathode is the electrode where reduction occurs.
Reduction, in this case, refers to the gain of electrons.
Therefore, the correct answer is A, "An electrode where reduction takes place and electrons are gained".

MCQ 28:

What is the oxidation number of Chromium (Cr) in Potassium Dichromate (K₂Cr₂O₇)?

A) +14.
B) +12.
C) +6.
D) None of the above.

Topic: Determining Oxidation State in a Compound

Correct Answer: C) +6.

Detailed Hint:

Oxidation numbers are determined by assigning electrons to different atoms within a compound based on certain rules and guidelines.
In the case of K₂Cr₂O₇, Chromium (Cr) has an oxidation number of +6, while Potassium (K) has an oxidation state of +1 and Oxygen (O) has -2.
Therefore, the correct answer is C, "+6".

MCQ 29:

What is the function of a salt bridge in a galvanic cell?

A) Transfers electrons between the two half cells.
B) Transfers ions between the two half cells.
C) Determines the emf value of the cell.
D) Conducts electrolysis.

Topic: Function of a Salt Bridge in a Galvanic Cell

Correct Answer: B) Transfers ions between the two half cells.

Detailed Hint:

A salt bridge serves an essential role in a galvanic cell, which is an electrochemical cell that uses spontaneous redox reactions to generate electricity.
Its primary function is to maintain electrical neutrality within the internal circuit, preventing the cell from rapidly running its course.
It accomplishes this by transferring ions from one half cell to the other.
Therefore, the correct answer is B, "Transfers ions between the two half cells".

Question 30:

In the following chemical reaction, which element acts as a reducing agent?

Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g)

A) Zinc (Zn)
B) Hydrogen (H)
C) Sulfur (S)
D) Oxygen (O)

Topic: Identifying the Reducing Agent in a Chemical Reaction

Correct Answer: A) Zinc (Zn)

Detailed Hint:

In a redox reaction, the reducing agent is the element or compound that donates electrons, undergoing oxidation in the process.
In the given equation, Zinc (Zn) transforms into Zn⁺², signifying that it loses electrons and, thus, is oxidized.
Therefore, the correct answer is A, "Zinc (Zn)".

Question 31:

What is the purpose of a cathode in a galvanic cell?

A) An electrode where oxidation takes place and electrons are lost.
B) A fluid that conducts electricity.
C) An electrode where reduction occurs and electrons are gained.
D) None of the above.

Topic: The Role of a Cathode in a Galvanic Cell

Correct Answer: C) An electrode where reduction occurs and electrons are gained.

Detailed Hint:

In a galvanic cell, the cathode plays a crucial role in facilitating the cell's overall redox reaction.
The cathode is the electrode where reduction, or the gain of electrons, takes place.
Therefore, the correct answer is C, "An electrode where reduction occurs and electrons are gained".

Electrochemistry Test 1

MCQ 1:

Topic: Balancing of Chemical Equations in Basic Media

MCQ 2:

Topic: Electrolysis and Reduction Process

MCQ 3:

Topic: Chemical Reactions in Electrochemical Series

MCQ 4:

Topic: Oxidation-Reduction (Redox) Reactions

MCQ 5:

Topic: Role of Salt Bridge in Electrochemical Cells

MCQ 6:

Topic: Relationship between Oxidizing Agent Strength and Reduction Potential

MCQ 7:

Topic: Metal Reactivity and Reduction Potentials

MCQ 8:

Topic: Conductivity of Different Materials

MCQ 9:

Topic: Significance of Electrochemical Series

MCQ 10:

Topic: Electrolysis and Product Collection

MCQ 11:

Topic: Electrochemical Series and Reduction Potentials

MCQ 12:

Topic: Oxidation States of Free Elements

MCQ 13:

Topic: Electrolysis and Ion Reduction

MCQ 14:

Topic: Applications of Electrochemical Series

Question 15:

Topic: Factors Affecting Oxidizing Power

Question 16:

Topic: Metal Deposition in Electrolysis

Question 17:

Topic: Properties of Standard Hydrogen Electrode

Question 18:

Topic: Function of Salt Bridge in Electrolytic Cells

Question 19:

Topic: Determining the Best Reducing Agent

Question 20:

Topic: Identification of Cathode in Electrolysis

Question 21:

Topic: Oxidation State Stability Sequence

MCQ 22:

Topic: Potential of Standard Hydrogen Electrode

MCQ 23:

Topic: Determining Oxidation State in a Compound

MCQ 24:

Topic: Oxidation State in a Chemical Compound

MCQ 25:

Topic: Identification of Redox Reactions

MCQ 26:

Topic: Oxidation in a Chemical Reaction

MCQ 27:

Topic: Definition of a Cathode

MCQ 28:

Topic: Determining Oxidation State in a Compound

MCQ 29:

Topic: Function of a Salt Bridge in a Galvanic Cell

Question 30:

Topic: Identifying the Reducing Agent in a Chemical Reaction

Question 31:

Topic: The Role of a Cathode in a Galvanic Cell

Test Results