Question 1

How might electrolysis be used to raise the hull of a sunken ship?

Accepted Answer

The gaseous products of electrolysis could be collected with large bags attached to the hull of the ship, which would inflate with the gas and buoy the ship upwards. This method is feasible and has been used in the past to raise sunken ships. The other options either rely on the wrong mechanism for raising the ship or have limitations that make them impractical.

Question 2

In a battery,the following oxidation-reduction reactions are taking place: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What is being formed at the anode?

Accepted Answer

The answer of In a battery,the following oxidation-reduction reactions are...

Question 3

Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?

Accepted Answer

The zinc walls in a battery are part of the chemical reaction that generates electricity. As the battery is used, the zinc is gradually converted into zinc ions, meaning that thicker zinc walls can provide more material for the reaction, thereby allowing the battery to last longer.

Question 4

What is the primary difference between a fuel cell and a battery?

Accepted Answer

The primary difference between a fuel cell and a battery is that fuel cells can be refueled, while batteries run down and need to be recharged. This means that fuel cells have a continuous source of energy, while batteries have a limited amount of energy before they need to be recharged.

Question 5

Your car lights were left on while you were shopping,and now your car battery is dead.Has the pH of the battery fluid increased or decreased?

Accepted Answer

When a car battery discharges, the sulfuric acid in the electrolyte is consumed, leading to an increase in pH (making it less acidic).

Question 6

Sodium metal is

Accepted Answer

Sodium metal is oxidized in the production of aluminum.

Question 7

What is one of the advantages of a fuel cell?

Accepted Answer

Fuel cells have the advantage of being able to run for a long time as long as fuel is added, being more efficient than combustion, and having lower emissions of pollutants. Therefore, all of the options are advantages of fuel cells.

Question 8

What is one of the drawbacks to using fuel cells?

Accepted Answer

Fuel cells often use hydrogen as a fuel, which is difficult to store and transport safely due to its high flammability and the fact that it is a gas at room temperature. This makes handling the fuel for fuel cells a significant drawback.

Question 9

A major source of chlorine gas, $\mathrm { Cl } _ { 2 }$ ,is from the electrolysis of brine,which is concentrated salt water, $\mathrm { NaCl } ( \mathrm { aq } )$ What is the sign of the electrode where the chlorine gas is formed? Is it negative or positive?

Accepted Answer

Chlorine gas is formed at the positive electrode (anode) during the electrolysis of brine because chloride ions (Cl-) lose electrons (are oxidized) to form chlorine gas (Cl2).

Question 10

Why might disposing of a lead-acid battery,nickel-cadmium battery or mercury battery in a landfill be a bad thing?

Accepted Answer

Lead-acid, nickel-cadmium, and mercury batteries all contain toxic metals that can leak out of the landfill and contaminate the surrounding land, water, and air. These metals can harm human health and the environment. Therefore, it is not a good idea to dispose of such batteries in a landfill. Other disposal methods, such as recycling, should be considered.

Question 11

How is electrolysis different from what is going on chemically inside a battery?

Accepted Answer

Electrolysis and what happens chemically inside a battery involve the same process of transferring electrons between electrodes, but in opposite directions. In a battery, chemical energy is converted to electrical energy, whereas in electrolysis, electrical energy is used to drive a chemical reaction.

Question 12

Why don't the electrodes of a fuel cell deteriorate the way the electrodes of a battery do?

Accepted Answer

Fuel cells continuously convert fuel into electricity as long as there is a supply of fuel and oxygen, unlike batteries which store a finite amount of energy and deteriorate as their chemical reactants are consumed.

Question 13

In a battery,if the following oxidation-reduction reactions takes place normally: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What reaction would be taking place if you were charging the battery?

Accepted Answer

When the battery is being charged, the reverse reaction of the discharge reaction occurs. Therefore, the oxidized species (MnO and Zn) are reduced back to their original form (MnS and ZnO). The reverse of the given reaction would be: 2 MnO₂ + Zn → Mn₂O₃ + ZnO.

Question 14

Jewelry is often manufactured by electroplating an expensive metal such as gold over a cheaper metal.A setup for this process can be sketched as follows:  What would happen if the battery connections were suddenly reversed?

Accepted Answer

Reversing the battery connections would result in the gold electrode becoming the cathode instead of the anode. This would cause gold ions in solution to begin to electroplate onto the gold electrode, resulting in a thicker coating of gold. However, this would also mean that the cheaper metal which was previously being electroplated with gold would no longer be plated, as it would now become the anode.

Question 15

A major source of chlorine gas, $\mathrm { Cl } _ { 2 }$ ,is from the electrolysis of brine,which is concentrated salt water, $\mathrm { NaCl } ( \mathrm { aq } )$ Which of the following is the balanced chemical reaction for this electrolysis reaction?

Accepted Answer

The balanced chemical reaction for the electrolysis of brine (NaCl) produces sodium hydroxide (NaOH), chlorine gas ($\mathrm { Cl } _ { 2 }$), and hydrogen gas ($\mathrm { H } _ { 2 }$).

Question 16

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H₂ + O₂ → 2 H₂O What is the fuel?

Accepted Answer

Based on the given reaction, H₂ is being oxidized and combined with O₂ to form H₂O. Therefore, H₂ is the fuel.

Question 17

Why is recycling of aluminum better for the environment than electrolysis of bauxite (an aluminum ore)?

Accepted Answer

Recycling of aluminum requires less energy compared to the electrolysis of bauxite. The process of electrolysis consumes a significant amount of energy, and the extraction of aluminum from bauxite also requires extensive mining activities, leading to habitat destruction and soil erosion. Recycling aluminum helps to reduce greenhouse gas emissions, conserve energy, and preserve natural resources. Hence, recycling aluminum is a better choice for the environment.

Question 18

For the following electrolysis reaction: 2 AlOF₃^-2 + C → 2 Al + CO₂ + F^- Where would the aluminum form?

Accepted Answer

During electrolysis, metals form at the cathode because they gain electrons (reduction process). Aluminum, being a metal, will form at the cathode in this reaction.

Question 19

In a battery,the following oxidation-reduction reactions are taking place: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What is being formed at the cathode?

Accepted Answer

At the cathode, reduction takes place, which means electrons are gained. In the given reaction, ZnO is reduced to form Zn, which means Zn is being formed at the cathode. Therefore, option A is the correct answer.

Question 20

In one type of fuel cell,the following oxidation-reduction reactions are taking place: 2 H₂+ O₂ → 2 H₂O What is the oxidant?

Accepted Answer

The oxidant is the substance that is being reduced, which in this case is O₂.

Quiz 18: Two Classes of Chemical Reactions

How might electrolysis be used to raise the hull of a sunken ship?

In a battery,the following oxidation-reduction reactions are taking place: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What is being formed at the anode?

Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?

What is the primary difference between a fuel cell and a battery?

Your car lights were left on while you were shopping,and now your car battery is dead.Has the pH of the battery fluid increased or decreased?

Sodium metal is

What is one of the advantages of a fuel cell?

What is one of the drawbacks to using fuel cells?

A major source of chlorine gas, $\mathrm { Cl } _ { 2 }$ ,is from the electrolysis of brine,which is concentrated salt water, $\mathrm { NaCl } ( \mathrm { aq } )$ What is the sign of the electrode where the chlorine gas is formed? Is it negative or positive?

Why might disposing of a lead-acid battery,nickel-cadmium battery or mercury battery in a landfill be a bad thing?

How is electrolysis different from what is going on chemically inside a battery?

Why don't the electrodes of a fuel cell deteriorate the way the electrodes of a battery do?

In a battery,if the following oxidation-reduction reactions takes place normally: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What reaction would be taking place if you were charging the battery?

Jewelry is often manufactured by electroplating an expensive metal such as gold over a cheaper metal.A setup for this process can be sketched as follows: What would happen if the battery connections were suddenly reversed?

A major source of chlorine gas, $\mathrm { Cl } _ { 2 }$ ,is from the electrolysis of brine,which is concentrated salt water, $\mathrm { NaCl } ( \mathrm { aq } )$ Which of the following is the balanced chemical reaction for this electrolysis reaction?

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H₂ + O₂ → 2 H₂O What is the fuel?

Why is recycling of aluminum better for the environment than electrolysis of bauxite (an aluminum ore) ?

For the following electrolysis reaction: 2 AlOF₃^-2 + C → 2 Al + CO₂ + F^- Where would the aluminum form?

In a battery,the following oxidation-reduction reactions are taking place: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What is being formed at the cathode?

In one type of fuel cell,the following oxidation-reduction reactions are taking place: 2 H₂+ O₂ → 2 H₂O What is the oxidant?

Quiz 18: Two Classes of Chemical Reactions

How might electrolysis be used to raise the hull of a sunken ship?

In a battery,the following oxidation-reduction reactions are taking place: Mn2O3 + ZnO → 2 MnO2 + Zn What is being formed at the anode?

Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?

What is the primary difference between a fuel cell and a battery?

Your car lights were left on while you were shopping,and now your car battery is dead.Has the pH of the battery fluid increased or decreased?

Sodium metal is

What is one of the advantages of a fuel cell?

What is one of the drawbacks to using fuel cells?

A major source of chlorine gas, Cl2\mathrm { Cl } _ { 2 }Cl2​ ,is from the electrolysis of brine,which is concentrated salt water, NaCl(aq) \mathrm { NaCl } ( \mathrm { aq } ) NaCl(aq) What is the sign of the electrode where the chlorine gas is formed? Is it negative or positive?

Why might disposing of a lead-acid battery,nickel-cadmium battery or mercury battery in a landfill be a bad thing?

How is electrolysis different from what is going on chemically inside a battery?

Why don't the electrodes of a fuel cell deteriorate the way the electrodes of a battery do?

In a battery,if the following oxidation-reduction reactions takes place normally: Mn2O3 + ZnO → 2 MnO2 + Zn What reaction would be taking place if you were charging the battery?

Jewelry is often manufactured by electroplating an expensive metal such as gold over a cheaper metal.A setup for this process can be sketched as follows: What would happen if the battery connections were suddenly reversed?

A major source of chlorine gas, Cl2\mathrm { Cl } _ { 2 }Cl2​ ,is from the electrolysis of brine,which is concentrated salt water, NaCl(aq) \mathrm { NaCl } ( \mathrm { aq } ) NaCl(aq) Which of the following is the balanced chemical reaction for this electrolysis reaction?

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O What is the fuel?

Why is recycling of aluminum better for the environment than electrolysis of bauxite (an aluminum ore) ?

For the following electrolysis reaction: 2 AlOF3-2 + C → 2 Al + CO2 + F- Where would the aluminum form?

In a battery,the following oxidation-reduction reactions are taking place: Mn2O3 + ZnO → 2 MnO2 + Zn What is being formed at the cathode?

In one type of fuel cell,the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O What is the oxidant?

In a battery,the following oxidation-reduction reactions are taking place: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What is being formed at the anode?

A major source of chlorine gas, $\mathrm { Cl } _ { 2 }$ ,is from the electrolysis of brine,which is concentrated salt water, $\mathrm { NaCl } ( \mathrm { aq } )$ What is the sign of the electrode where the chlorine gas is formed? Is it negative or positive?

In a battery,if the following oxidation-reduction reactions takes place normally: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What reaction would be taking place if you were charging the battery?

A major source of chlorine gas, $\mathrm { Cl } _ { 2 }$ ,is from the electrolysis of brine,which is concentrated salt water, $\mathrm { NaCl } ( \mathrm { aq } )$ Which of the following is the balanced chemical reaction for this electrolysis reaction?

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H₂ + O₂ → 2 H₂O What is the fuel?

For the following electrolysis reaction: 2 AlOF₃^-2 + C → 2 Al + CO₂ + F^- Where would the aluminum form?

In a battery,the following oxidation-reduction reactions are taking place: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What is being formed at the cathode?

In one type of fuel cell,the following oxidation-reduction reactions are taking place: 2 H₂+ O₂ → 2 H₂O What is the oxidant?