Electrochemistry Test 2

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MCQs 1:

What is the oxidation state of carbon in glucose (C₆H₁₂O₆)?

A) Zero
B) One
C) Two
D) Four

Topic: Oxidation States in Chemical Reactions

Correct Answer: A) Zero

Detailed Hint:

The oxidation state represents the hypothetical charge that an atom would have if all bonds were completely ionic.
In the chemical formula for glucose, C₆H₁₂O₆, we need to find the oxidation state of carbon.
For this, we use the formula: Oxidation state of carbon (x) * the number of carbon atoms (6) + the total oxidation state of Hydrogen (12) + the total oxidation state of Oxygen (-12) = 0. This gives us the equation, 6x + 12 - 12 = 0.
Solving this equation, we find that the oxidation state of carbon in glucose is zero, which makes option A the correct answer.

MCQs 2:

What are the conditions necessary to have a standard hydrogen electrode?

A) Temperature 25°C, pressure 1 atm, and H⁺ concentration 1M
B) Temperature 0°C, pressure 1 atm, and H⁺ concentration 1M
C) Temperature 25°C, pressure 2 atm, and H⁺ concentration 1M
D) Temperature 25°C, pressure 1 atm, and H⁺ concentration 2M

Topic: Electrochemical Standards in Chemistry

Correct Answer: A) Temperature 25°C, pressure 1 atm, and H⁺ concentration 1M

Detailed Hint:

A standard hydrogen electrode is a reference electrode used in electrochemical studies.
It is defined by specific environmental conditions which include a temperature of 25°C, a pressure of 1 atmosphere, and a hydrogen ion concentration of 1M.
Therefore, the correct answer is A, "Temperature 25°C, pressure 1 atm, and H⁺ concentration 1M".

MCQs 3:

On what type of reaction is an electrochemical cell based?

A) Acid-Base reaction
B) Redox reaction
C) Nuclear reaction
D) Catalytic reaction

Topic: Principles of Electrochemical Cells

Correct Answer: B) Redox reaction

Detailed Hint:

Electrochemical cells function through reactions that involve the transfer of electrons.
This kind of reaction is referred to as a reduction-oxidation or redox reaction.
Therefore, the correct answer is B, "Redox reaction".

MCQs 4:

Which branch of chemistry deals with the relationship between electricity and chemical reactions?

A) Chemical kinetics
B) Electrochemistry
C) Stoichiometry
D) Thermochemistry

Topic: Branches of Chemistry

Correct Answer: B) Electrochemistry

Detailed Hint:

The branch of chemistry that studies the relationship between chemical reactions and electricity is called electrochemistry.
This field involves the study of reactions which take place at the interface of an electrode, usually a metal or a semiconductor, and an ionic conductor, the electrolyte.
Therefore, the correct answer is B, "Electrochemistry".

MCQs 5:

What would the reaction be if a strip of Cu metal is placed in a solution of FeSO₄?

A) Cu will be precipitated.
B) Fe is precipitated.
C) Cu and Fe both dissolve.
D) None of these

Topic: Reactions in Electrochemistry

Correct Answer: D) None of these

Detailed Hint:

This question revolves around the understanding of reaction mechanisms in electrochemistry, particularly the reactivity of metals.
The electrochemical series determines which metals can replace others in compounds. In this case, Cu, being lower than Fe+2 in the electrochemical series, cannot replace Fe in FeSO₄.
Therefore, the correct answer is D, "None of these". No reaction takes place under these circumstances.

MCQs 6:

What is the term for the process of breaking down a compound using electricity?

A) Electrolysis
B) Electrolyte
C) Electrokinesis
D) None of the above

Topic: Principles of Electrolysis

Correct Answer: A) Electrolysis

Detailed Hint:

The term for breaking down a compound using electricity is a fundamental concept in electrochemistry.
Ionic substances can be decomposed into their constituent elements under the influence of an electric current in a process called electrolysis.
Therefore, the correct answer is A, "Electrolysis".

MCQs 7:

What is the oxidation state of oxygen in peroxides?

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

Topic: Oxidation States in Chemistry

Correct Answer: B) -1

Detailed Hint:

Understanding oxidation states is key to understanding many reactions in chemistry, including the behavior of oxygen in different compounds.
In peroxides such as hydrogen peroxide (H₂O₂), each hydrogen has an oxidation state of +1, thus each oxygen must have an oxidation state of -1 to balance it out.
Therefore, the correct answer is B, "-1".

Question 8:

What do we call a non-spontaneous redox reaction that is carried out by employing electrical current?

A) Decomposition of the substances
B) Cracking
C) Hydrolysis
D) Electrolysis

Topic: Electrochemical Reactions

Correct Answer: D) Electrolysis

Detailed Hints:

This question involves knowledge of electrochemical processes, specifically understanding the phenomenon of redox reactions.
When a non-spontaneous redox reaction is facilitated by an electric current, an intricate process takes place involving the movement and exchange of electrons and ions, which lead to reduction and oxidation reactions.
Therefore, the correct answer is D, "Electrolysis", which is the process describing this phenomenon.

Question 9:

What is the algebraic total of the oxidation numbers of all elements present in neutral molecules?

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

Topic: Oxidation Numbers in Neutral Molecules

Correct Answer: C) 0

Detailed Hints:

This question relates to the basic understanding of oxidation numbers and their role in chemical reactions.
For neutral molecules, the algebraic sum of oxidation numbers of all elements involved should always be zero.
Therefore, the correct answer is C, "0".

Question 10:

In which of the following reactions does hydrogen function as an oxidizing agent?

A) H2 + Cl2 ⟶ 2HCl
B) C2H4 + H2 ⟶ C2H6
C) Na + H2 ⟶ 2NaH
D) N2 + 3H2 ⟶ 2NH3

Topic: Hydrogen as an Oxidizing Agent

Correct Answer: C) Na + H2 ⟶ 2NaH

Detailed Hints:

This question tests the understanding of redox reactions, specifically the role of hydrogen as an oxidizing agent.
In the provided reactions, hydrogen acts as an oxidizing agent in the reaction C) Na + H2 ⟶ 2NaH. Here, hydrogen gains electrons, indicating its role as an oxidizing agent.
Therefore, the correct answer is C) Na + H2 ⟶ 2NaH.

Question 11:

Why are the coinage metals (Cu, Ag, and Au) considered to be the least reactive?

A) They have a negative reduction potential.
B) They possess a negative oxidation potential.
C) They have a positive reduction potential.
D) Their oxidation potential is positive.

Topic: Reactivity of Coinage Metals

Correct Answer: C) They have a positive reduction potential.

Detailed Hints:

This question involves understanding the reactivity of coinage metals (Copper, Silver, and Gold) in relation to their reduction potential.
Coinage metals are least reactive due to their high positive reduction potentials (Cu+2 = +0.34V, Ag+ = 0.78V, Au3+ = +1.50V).
Hence, the right answer is C, "They have a positive reduction potential".

Question 12:

Which kind of energy is utilized in the process of electrolysis where a chemical reaction ensues?

A) Chemical energy is used.
B) Kinetic energy is used.
C) Heat energy is employed.
D) Electrical energy is expended.

Topic: Energy in Electrolysis

Correct Answer: D) Electrical energy is expended.

Detailed Hints:

This query tests the understanding of the energy transformation that occurs during electrolysis.
During electrolysis, electrical energy is converted into chemical energy, facilitating a chemical reaction.
Thus, the correct answer is D, "Electrical energy is expended".

Question 13:

Which is the appropriate definition of oxidation among the following options?

A) It is the addition of oxygen, addition of hydrogen, and removal of electrons.
B) It is the removal of an electronegative element, removal of an electropositive element, and gain of electrons.
C) It involves the addition of an electronegative element, removal of an electropositive element, and gain of electrons.
D) Oxidation is the addition of oxygen, removal of hydrogen, and loss of electrons.

Topic: Definition of Oxidation

Correct Answer: D) Oxidation is the addition of oxygen, removal of hydrogen, and loss of electrons.

Detailed Hints:

The question tests your understanding of the definition of oxidation in terms of what it involves.
Oxidation is typically defined as the addition of oxygen, removal of hydrogen, and loss of electrons.
Therefore, the correct answer is D, "Oxidation is the addition of oxygen, removal of hydrogen, and loss of electrons".

Question 14:

What is likely the electrolyte if Hydrogen forms at the cathode and Chlorine at the anode during electrolysis?

A) NaCl is the electrolyte.
B) The electrolyte is AgCl.
C) CuCl2 is the electrolyte.
D) The electrolyte is H2SO4.

Topic: Identification of Electrolyte

Correct Answer: A) NaCl is the electrolyte.

Detailed Hints:

This question requires you to identify the correct electrolyte based on the products formed at the cathode and anode during electrolysis.
In this scenario, Hydrogen is formed at the cathode and Chlorine at the anode, indicating that the electrolyte is likely NaCl.
Therefore, the correct answer is A, "NaCl is the electrolyte".

Question 15:

What value is assigned to the standard hydrogen electrode in terms of fixed potential?

A) The fixed potential is 10 V.
B) It's set at 1.0 V.
C) The potential is fixed at 0.1 V.
D) It's measured as 0.0001 V.

Topic: Standard Hydrogen Electrode

Correct Answer: D) It's measured as 0.0001 V.

Detailed Hint:

This question tests your knowledge of the potential assigned to the standard hydrogen electrode.
It is crucial to know that the standard hydrogen electrode has an arbitrary fixed potential that is close to zero.
In light of the given options, the best answer is D, "It's measured as 0.0001 V".

Question 16:

Given the reduction potentials of four elements, which one is the most potent reducing agent?

A) The element with a reduction potential of 2.17.
B) The element with a reduction potential of 0.98.
C) The element with a reduction potential of -1.3.
D) The element with a reduction potential of -2.3.

Topic: Reducing Agent Identification

Correct Answer: D) The element with a reduction potential of -2.3.

Detailed Hint:

This question calls for understanding of the concept of reduction potentials and their relationship with reducing agent strength.
An element with a negative reduction potential is likely to be a strong reducing agent.
Hence, the correct answer is D, "The element with a reduction potential of -2.3".

Question 17:

How does the oxidation number of an element change during an oxidation process?

A) The oxidation number increases.
B) It decreases.
C) There is no change in the oxidation number.
D) The oxidation number can either increase or decrease.

Topic: Oxidation Process and Oxidation Number

Correct Answer: A) The oxidation number increases.

Detailed Hint:

This question evaluates your comprehension of how an oxidation process affects the oxidation number of an element.
In an oxidation process, electrons are removed which causes the oxidation number of the element to increase.
Therefore, the correct answer is A, "The oxidation number increases".

Question 18:

What value is typically assigned to the electrode potential of the standard hydrogen electrode?

A) The value is usually positive.
B) It’s typically a negative value.
C) Zero is the common value.
D) The value can depend on the specific situation.

Topic: Electrode Potential of Standard Hydrogen Electrode

Correct Answer: C) Zero is the common value.

Detailed Hint:

This question explores your knowledge of the value that is typically assigned to the electrode potential of the standard hydrogen electrode.
The standard hydrogen electrode potential is arbitrarily chosen as zero.
Consequently, the correct answer is C, "Zero is the common value".

Question 19:

What is the primary function of a salt bridge?

A) Its main role is to maintain the flow of electrons.
B) It is primarily used to prevent the accumulation of charges.
C) The salt bridge is used to create resistivity.
D) All of the above are functions of the salt bridge.

Topic: Function of a Salt Bridge

Correct Answer: B) It is primarily used to prevent the accumulation of charges.

Detailed Hint:

This question assesses your understanding of the primary function of a salt bridge in an electrochemical cell.
A salt bridge serves primarily to prevent the build-up of positive charges at the anode and negative charges at the cathode.
Therefore, the correct answer is B, "It is primarily used to prevent the accumulation of charges".

Question 20:

What is the standard value for the electrode potential of both cathode and anode in the Standard Hydrogen Electrode?

A) It's always taken as one.
B) Zero is always the value.
C) The values are usually distinct.
D) The values are generally the same.

Topic: Standard Hydrogen Electrode Potential

Correct Answer: B) Zero is always the value.

Detailed Hint:

This question gauges your understanding of the standard electrode potential value for both the cathode and anode in the Standard Hydrogen Electrode (SHE).
The SHE potential is universally accepted as zero.
Consequently, the correct answer is B, "Zero is always the value".

Question 21:

What characterizes a redox reaction?

A) It’s a reaction that occurs in a solution.
B) It’s an ion-combination reaction.
C) It involves the transfer of electrons.
D) It involves the transfer of protons.

Topic: Redox Reactions

Correct Answer: C) It involves the transfer of electrons.

Detailed Hint:

This question seeks to assess your understanding of the core characteristics of a redox reaction.
Redox, short for reduction-oxidation reaction, primarily involves the change in oxidation state of atoms through electron transfer.
Therefore, the correct answer is C, "It involves the transfer of electrons".

Question 22:

What is the name of a cell where a spontaneous redox reaction generates electrical energy?

A) Electrolytic cell.
B) Electrochemical cell.
C) Voltaic cell.
D) Biological cell.

Topic: Spontaneous Redox Reaction Cells

Correct Answer: C) Voltaic cell.

Detailed Hints:

This question aims to test your knowledge about the type of cell in which a spontaneous redox reaction occurs to produce electric current.
A voltaic cell, also known as a galvanic cell, is an electrochemical cell that derives electrical energy from spontaneous redox reactions.
As a result, the correct answer is C, "Voltaic cell".

Question 23:

What is the impact of temperature on metallic and electrolytic conduction?

A) Metallic conduction improves while electrolytic conduction deteriorates.
B) Metallic conduction deteriorates while electrolytic conduction improves.
C) Both types of conduction weaken.
D) Both types of conduction improve.

Topic: Effects of Temperature on Conduction

Correct Answer: B) Metallic conduction deteriorates while electrolytic conduction improves.

Detailed Hints:

This question tests your understanding of how temperature changes influence metallic and electrolytic conduction.
Increased temperatures cause a rise in resistance, which reduces metallic conduction, while electrolytic conduction gets a boost due to enhanced ion energy.
As a result, the correct answer is B, "Metallic conduction deteriorates while electrolytic conduction improves".

Question 24:

Where does reduction invariably occur?

A) At the cathode.
B) At the anode.
C) At both electrodes.
D) At none of the electrodes.

Topic: Site of Reduction

Correct Answer: A) At the cathode.

Detailed Hint:

This question probes your familiarity with the site of reduction in electrochemical reactions.
Electrons enter at the cathode, and the process of gaining electrons is termed reduction.
Therefore, the correct answer is A, "At the cathode".

Question 25:

Why does a zinc rod act as an anode in a Daniell cell but as a cathode when paired with an aluminum electrode?

A) The standard reduction potential of Zn is greater than Al.
B) The standard reduction potential of Zn is less than Al.
C) The standard reduction potential of Zn is equal to Al.
D) The standard reduction potential of Zn equals zero.

Topic: Zinc Rod in Daniell Cell and with Aluminum Electrode

Correct Answer: A) The standard reduction potential of Zn is greater than Al.

Detailed Hint:

This question evaluates your understanding of the role of the standard reduction potential in determining which electrode a zinc rod acts as in different setups.
When paired with an aluminum electrode, the zinc rod acts as the cathode because its standard reduction potential is higher than that of aluminum.
As a result, the correct answer is A, "The standard reduction potential of Zn is greater than Al".

Question 26:

In an acidic solution, what is added to balance oxygen in the ion-electron method?

A) Oxygen (O2)
B) Water (H2O)
C) Ions
D) None of the above

Topic: Balancing Oxygen in Ion-Electron Method

Correct Answer: B) Water (H2O)

Detailed Hint:

This question is assessing your understanding of the Ion-Electron Method, specifically how to balance oxygen in acidic solutions.
In acidic solutions, water (H2O) is used to balance the oxygen atoms.
Therefore, the correct answer is B, "Water (H2O)".

Question 27:

What term is used for the process where electric current is utilized to carry out a non-spontaneous redox reaction?

A) Electrolyte
B) Electrolysis
C) Metallic conduction
D) Combustion

Topic: Non-Spontaneous Redox Reactions

Correct Answer: B) Electrolysis

Detailed Hint:

This question aims to examine your knowledge on the terminologies and processes involved in redox reactions.
The process where electric current is used to facilitate a non-spontaneous redox reaction is called electrolysis.
Hence, the correct answer is B, "Electrolysis".

Question 28:

In which of the following does oxygen display an oxidation state of zero?

A) Carbon Monoxide (CO)
B) Oxygen (O2)
C) Nitric Oxide (NO)
D) Nitrous Oxide (N2O)

Topic: Oxidation State of Oxygen

Correct Answer: B) Oxygen (O2)

Detailed Hint:

This question tests your understanding of the concept of oxidation states, specifically referring to the element oxygen.
In an oxygen molecule (O2), each oxygen atom has an oxidation state of zero.
Thus, the correct answer is B, "Oxygen (O2)".

Question 29:

Which compound listed below carries the highest oxidation state for sulfur?

A) Sulfur Dioxide (SO2)
B) Sulfur Trioxide (SO3)
C) Hydrogen Sulfide (H2S)
D) Sulfurous Acid (H2SO3)

Topic: Oxidation State of Sulfur

Correct Answer: B) Sulfur Trioxide (SO3)

Detailed Hint:

This question aims to evaluate your understanding of the oxidation states, more specifically of the element sulfur in the given compounds.
Among the listed compounds, sulfur trioxide (SO3) exhibits the highest oxidation state for sulfur, which is +6.
Therefore, the correct answer is B, "Sulfur Trioxide (SO3)".

Question 30:

Referencing the provided diagram, which electrode reaction will take place?

Diagram will be uploaded soon

A) Reaction A
B) Reaction B
C) Reaction C
D) Reaction D

Topic: Electrode Reactions

Correct Answer: D) Reaction D

Detailed Hint:

This question assesses your comprehension of oxidation and reduction reactions occurring at different electrodes.
At the anode, zinc is oxidized to Zn²⁺ and electrons, indicating zinc is gradually converted into Zn²⁺.
At the cathode, reduction occurs as H⁺ ions are reduced to hydrogen gas, which is continuously released.
Hence, the correct answer is D, "Reaction D".

Electrochemistry Test 2

MCQs 1:

Topic: Oxidation States in Chemical Reactions

MCQs 2:

Topic: Electrochemical Standards in Chemistry

MCQs 3:

Topic: Principles of Electrochemical Cells

MCQs 4:

Topic: Branches of Chemistry

MCQs 5:

Topic: Reactions in Electrochemistry

MCQs 6:

Topic: Principles of Electrolysis

MCQs 7:

Topic: Oxidation States in Chemistry

Question 8:

Topic: Electrochemical Reactions

Question 9:

Topic: Oxidation Numbers in Neutral Molecules

Question 10:

Topic: Hydrogen as an Oxidizing Agent

Question 11:

Topic: Reactivity of Coinage Metals

Question 12:

Topic: Energy in Electrolysis

Question 13:

Topic: Definition of Oxidation

Question 14:

Topic: Identification of Electrolyte

Question 15:

Topic: Standard Hydrogen Electrode

Question 16:

Topic: Reducing Agent Identification

Question 17:

Topic: Oxidation Process and Oxidation Number

Question 18:

Topic: Electrode Potential of Standard Hydrogen Electrode

Question 19:

Topic: Function of a Salt Bridge

Question 20:

Topic: Standard Hydrogen Electrode Potential

Question 21:

Topic: Redox Reactions

Question 22:

Topic: Spontaneous Redox Reaction Cells

Question 23:

Topic: Effects of Temperature on Conduction

Question 24:

Topic: Site of Reduction

Question 25:

Topic: Zinc Rod in Daniell Cell and with Aluminum Electrode

Question 26:

Topic: Balancing Oxygen in Ion-Electron Method

Question 27:

Topic: Non-Spontaneous Redox Reactions

Question 28:

Topic: Oxidation State of Oxygen

Question 29:

Topic: Oxidation State of Sulfur

Question 30:

Topic: Electrode Reactions

Test Results