Question 1

Which of the following reactions will occur spontaneously as written?

Accepted Answer

This reaction involves a spontaneous transfer of electrons from iron to chromium, which are both metals. The reactants are solids, and the products include a solid and an aqueous solution. These factors indicate that the reaction is likely to be spontaneous as written.

Question 2

Consider an electrochemical cell based on the reaction: 2H⁺ (aq)+ Sn (s)→ Sn²⁺ (aq)+ H₂ (g) Which of the following actions would not change the measured cell potential?

Accepted Answer

Adding more tin metal to the anode compartment will not affect the measured cell potential because the concentration of tin ions in the anode compartment is already at equilibrium. The measured cell potential depends only on the concentrations of the species involved in the cell reaction. Lowering the pH in the cathode compartment, increasing the tin (II) ion concentration in the anode compartment, or increasing the pressure of the hydrogen gas in the cathode compartment will all affect the concentrations of the species involved in the cell reaction, and therefore change the measured cell potential.

Question 3

What is the cathode in the hydrogen fuel cell?

Accepted Answer

The answer of What is the cathode in the hydrogen...

Question 4

In a lead-acid battery, the electrodes are consumed. In this battery,

Accepted Answer

In a lead-acid battery, the anode is made of lead (Pb) and the cathode is made of lead dioxide (PbO2). Both of these electrodes are consumed during the discharge process. Therefore, the correct choice is A, which states that the anode is Pb.

Question 5

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell __________.

Accepted Answer

In an electrolytic cell, a nonspontaneous reaction is forced to occur by applying an external electric current, whereas in a voltaic cell, a spontaneous reaction produces an electric current.

Question 6

Which of the following reactions will occur spontaneously as written?

Accepted Answer

The answer of Which of the following reactions will occur...

Question 7

__________ is oxidized in the following reaction: Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Accepted Answer

The answer of __________ is oxidized in the following reaction:...

Question 8

Which substance is serving as the oxidizing agent in the following reaction? 14H⁺ + Cr₂O₇^2- + 3Ni → 3Ni²⁺ + 2Cr³⁺ + 7H₂O

Accepted Answer

In the given reaction, the species Cr₂O₇^2- is being reduced to Cr³⁺. This indicates that Cr is undergoing a reduction, and therefore, a reduction agent is required. The only species containing an oxidizable element in the reaction is Cr₂O₇^2-, indicating that it is serving as the oxidizing agent. Therefore, the correct answer is C.

Question 9

Which one of the following types of elements is most likely to be a good oxidizing agent?

Accepted Answer

Halogens are highly electronegative and have a strong tendency to gain electrons, making them good oxidizing agents. They have a high electron affinity and are able to easily accept electrons from other substances, causing them to undergo reduction while the halogen is being reduced itself.

Question 10

What is the cathode in an alkaline battery?

Accepted Answer

The answer of What is the cathode in an alkaline...

Question 11

Cathodic protection of a metal pipe against corrosion usually entails

Accepted Answer

Cathodic protection involves making the metal pipe the cathode in an electrochemical cell, which reduces the potential difference between the pipe and the electrolyte, thus reducing the likelihood of corrosion. Attaching an active metal to make the pipe the anode (choice A) is actually anodic protection, which is less commonly used. Coating the pipe with another metal (choice B) is a form of sacrificial protection, where the more active metal corrodes instead of the pipe. Attaching a dry cell (choice D) is not an effective way to protect against corrosion. Coating the pipe with a fluoropolymer (choice E) may provide some chemical resistance but does not address the electrochemical process that causes corrosion.

Question 12

Which of the halogens in Table 20.1 is the strongest oxidizing agent?

Accepted Answer

Fluorine (F) is the strongest oxidizing agent among the halogens due to its highest electronegativity and ability to accept electrons more readily than other halogens.

Question 13

What is the anode in an alkaline battery?

Accepted Answer

In an alkaline battery, the anode is typically made up of zinc powder. When the battery is in use, the zinc particles are oxidized and release electrons, which flow through the circuit and power the device. Therefore, choice C (Zn powder) is the correct answer.

Question 14

__________ is reduced in the following reaction: Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Accepted Answer

The answer of __________ is reduced in the following reaction:...

Question 15

Which substance is serving as the reducing agent in the following reaction? 14H⁺ + Cr₂O₇^2- + 3Ni → 3Ni²⁺ + 2Cr³⁺ + 7H₂O

Accepted Answer

The answer of Which substance is serving as the reducing...

Question 16

Consider an electrochemical cell based on the reaction: 2H⁺ (aq)+ Sn (s)→ Sn²⁺ (aq)+ H₂ (g) Which of the following actions would change the measured cell potential?

Accepted Answer

The cell potential is influenced by the concentration of reactants and products (as per the Nernst equation), pH changes (which affect the concentration of H+ ions), and gas pressure (for reactions involving gases). Thus, all the given actions would change the measured cell potential.

Question 17

__________ is the oxidizing agent in the reaction below. Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Accepted Answer

In the given reaction, chromium is being reduced from a +6 oxidation state to a +3 oxidation state. This means it is gaining electrons and is therefore the species being reduced. The oxidizing agent is the species that is being reduced, so the oxidizing agent in this reaction is option A, Cr₂O₇^2-.

Question 18

__________ is the reducing agent in the reaction below. Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Accepted Answer

The answer of __________ is the reducing agent in the...

Question 19

The gain of electrons by an element is called __________.

Accepted Answer

The gain of electrons by an element is called reduction.

Question 20

Which one of the following is the best oxidizing agent?

Accepted Answer

The higher the reduction potential value, the better the oxidizing agent. Out of the given options, O₂ has the highest reduction potential value, making it the best oxidizing agent.

Quiz 20: Electrochemistry

Which of the following reactions will occur spontaneously as written?

Consider an electrochemical cell based on the reaction: 2H⁺ (aq) + Sn (s) → Sn²⁺ (aq) + H₂ (g) Which of the following actions would not change the measured cell potential?

What is the cathode in the hydrogen fuel cell?

In a lead-acid battery, the electrodes are consumed. In this battery,

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell __________.

Which of the following reactions will occur spontaneously as written?

__________ is oxidized in the following reaction: Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Which substance is serving as the oxidizing agent in the following reaction? 14H⁺ + Cr₂O₇^2- + 3Ni → 3Ni²⁺ + 2Cr³⁺ + 7H₂O

Which one of the following types of elements is most likely to be a good oxidizing agent?

What is the cathode in an alkaline battery?

Cathodic protection of a metal pipe against corrosion usually entails

Which of the halogens in Table 20.1 is the strongest oxidizing agent?

What is the anode in an alkaline battery?

__________ is reduced in the following reaction: Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Which substance is serving as the reducing agent in the following reaction? 14H⁺ + Cr₂O₇^2- + 3Ni → 3Ni²⁺ + 2Cr³⁺ + 7H₂O

Consider an electrochemical cell based on the reaction: 2H⁺ (aq) + Sn (s) → Sn²⁺ (aq) + H₂ (g) Which of the following actions would change the measured cell potential?

__________ is the oxidizing agent in the reaction below. Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

__________ is the reducing agent in the reaction below. Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

The gain of electrons by an element is called __________.

Which one of the following is the best oxidizing agent?

Quiz 20: Electrochemistry

Which of the following reactions will occur spontaneously as written?

Consider an electrochemical cell based on the reaction: 2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g) Which of the following actions would not change the measured cell potential?

What is the cathode in the hydrogen fuel cell?

In a lead-acid battery, the electrodes are consumed. In this battery,

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell __________.

Which of the following reactions will occur spontaneously as written?

__________ is oxidized in the following reaction: Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

Which substance is serving as the oxidizing agent in the following reaction? 14H+ + Cr2O72- + 3Ni → 3Ni2+ + 2Cr3+ + 7H2O

Which one of the following types of elements is most likely to be a good oxidizing agent?

What is the cathode in an alkaline battery?

Cathodic protection of a metal pipe against corrosion usually entails

Which of the halogens in Table 20.1 is the strongest oxidizing agent?

What is the anode in an alkaline battery?

__________ is reduced in the following reaction: Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

Which substance is serving as the reducing agent in the following reaction? 14H+ + Cr2O72- + 3Ni → 3Ni2+ + 2Cr3+ + 7H2O

Consider an electrochemical cell based on the reaction: 2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g) Which of the following actions would change the measured cell potential?

__________ is the oxidizing agent in the reaction below. Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

__________ is the reducing agent in the reaction below. Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

The gain of electrons by an element is called __________.

Which one of the following is the best oxidizing agent?

Consider an electrochemical cell based on the reaction: 2H⁺ (aq) + Sn (s) → Sn²⁺ (aq) + H₂ (g) Which of the following actions would not change the measured cell potential?

__________ is oxidized in the following reaction: Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Which substance is serving as the oxidizing agent in the following reaction? 14H⁺ + Cr₂O₇^2- + 3Ni → 3Ni²⁺ + 2Cr³⁺ + 7H₂O

__________ is reduced in the following reaction: Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Which substance is serving as the reducing agent in the following reaction? 14H⁺ + Cr₂O₇^2- + 3Ni → 3Ni²⁺ + 2Cr³⁺ + 7H₂O

Consider an electrochemical cell based on the reaction: 2H⁺ (aq) + Sn (s) → Sn²⁺ (aq) + H₂ (g) Which of the following actions would change the measured cell potential?

__________ is the oxidizing agent in the reaction below. Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

__________ is the reducing agent in the reaction below. Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O