Question 1

An electrochemical cell&#10;A) stores charge&#10;B) produces the electrical charges which then pass through a circuit&#10;C) uses a chemical reaction to separate charges

Accepted Answer

An electrochemical cell uses a chemical reaction to separate charges, creating a potential difference between two electrodes. This potential difference drives the flow of electrical charges through a circuit, producing an electric current. While an electrochemical cell does not store charge, it does generate and maintain a flow of charge.

Question 2

A disposable cell is classified as&#10;A) a battery&#10;B) a primary cell&#10;C) a secondary cell&#10;D) an electrolytic cell

Accepted Answer

A disposable cell, also known as a primary cell, is designed to be used until the chemicals inside are depleted, after which it is discarded. It cannot be recharged, unlike a secondary cell. Additionally, while a disposable cell does produce electrical energy, it is classified as a cell rather than a battery because batteries consist of multiple cells. Finally, while an electrolytic cell does produce electrical energy, it is used for specific chemical reactions and requires an external voltage source to function, making it different from a disposable cell.

Question 3

A rechargeable cell is classified as&#10;A) a battery&#10;B) a primary cell&#10;C) a secondary cell&#10;D) an electrolytic cell

Accepted Answer

A rechargeable cell is a secondary cell because it can be recharged multiple times by reversing the chemical reactions that occur during discharge. A primary cell, on the other hand, cannot be recharged and must be replaced once depleted. An electrolytic cell refers to a specific type of cell used for electrolysis, which is not necessarily rechargeable.

Question 4

The capacity of a cell is generally expressed in&#10;A) amperes&#10;B) volts&#10;C) ampere hours&#10;D) watts

Accepted Answer

The capacity of a cell refers to the amount of charge it can store, which is expressed in ampere hours (Ah). Option A is incorrect because amperes refers to the rate of flow of electric current, not the capacity of a cell. Option B is incorrect because volts refer to the electric potential difference between two points, not the capacity of a cell. Option D is incorrect because watts refer to the rate at which energy is being transferred, not the capacity of a cell.

Question 5

The capacity of cells may also be expressed in&#10;A) watt hours&#10;B) hours&#10;C) newton metres&#10;D) kilograms per cubic metre

Accepted Answer

The capacity of cells is typically expressed in watt hours (Wh), which is a measure of the amount of energy the cell can store and deliver.

Question 6

A cell's __________ determines the maximum value of continuous current a cell can supply without overheating&#10;A) capacity&#10;B) discharge rate&#10;C) state of charge&#10;D) relative density

Accepted Answer

The discharge rate of a cell dictates the maximum value of continuous current it can supply without overheating. The other options are not directly related to this characteristic of a cell.

Question 7

A 'Simple' or 'Voltaic' cell, comprises electrodes of __________ and __________ , with an electrolyte of __________&#10;A) carbon, zinc, dilute sulfuric acid&#10;B) lead sulfate, lead peroxide, dilute sulfuric acid&#10;C) zinc, copper, dilute sulfuric acid&#10;D) zinc, copper, potassium hydroxide

Accepted Answer

A simple or voltaic cell requires two electrodes of different metals and an electrolyte that allows ions to flow between the two electrodes. Choice C is the best option as it includes electrodes of zinc and copper, which are commonly used in simple cells, and a dilute sulfuric acid electrolyte. Choice A is incorrect as carbon is not typically used as an electrode in simple cells, and choice B includes lead electrodes, which are not commonly used in simple cells due to toxicity concerns. Choice D includes a potassium hydroxide electrolyte, which is not commonly used in simple cells.

Question 8

The electromotive force developed by any chemical cell depends on how far apart the electrodes are&#10;A) in terms of their distance&#10;B) in terms of their resistivities&#10;C) on the electrochemical series

Accepted Answer

The electromotive force developed by a chemical cell depends on the electrochemical series, which is a list of the standard electrode potentials of different elements and their ions. The position of the electrode in the series determines the direction of electron flow and the potential difference between the electrodes. The further apart the electrodes are on the series, the greater the potential difference and the higher the electromotive force of the cell. The distance between the electrodes and their resistivities do not affect the electromotive force of a chemical cell.

Question 9

In a cell having electrodes of zinc and copper, the negative electrode is always the&#10;A) zinc electrode&#10;B) copper electrode

Accepted Answer

In a cell having electrodes of zinc and copper, the negative electrode is always the zinc electrode. This is because during the reaction, oxidation occurs at the zinc electrode, and electrons are released, making it the negative electrode. Reduction occurs at the copper electrode, where the electrons are accepted, making it the positive electrode.

Question 10

The term 'polarisation' describes&#10;A) the polarity of a cell's electrodes&#10;B) the reverseal of a cell's polarity&#10;C) the formation of hydrogen gas bubbles on the positive electrode

Accepted Answer

Polarisation in the context of electrochemistry often refers to the process where gas bubbles, such as hydrogen, form on the electrodes of a cell, particularly on the cathode during electrolysis. This can interfere with the cell's operation by increasing its internal resistance and decreasing its efficiency.

Question 11

The effect of 'polarisation' is to&#10;A) determine the direction of current supplied by the cell&#10;B) reverse the direction of current supplied by the cell&#10;C) significantly reduce the electromotive force produced by the cell

Accepted Answer

The answer of The effect of 'polarisation' is to&#10;A) determine...

Question 12

The electrolyte used in a 'dry Leclanche' cell is a&#10;A) dilute sulfuric acid&#10;B) manganese dioxide gel&#10;C) manganese dioxide and powdered carbon&#10;D) ammonium chloride gel

Accepted Answer

The answer of The electrolyte used in a 'dry Leclanche'...

Question 13

The purpose of manganese dioxide and powdered carbon mixture in a 'dry Leclanche' cell is to&#10;A) act as an electrolyte&#10;B) reduce the cell's internal resistance&#10;C) act as a depolarising agent&#10;D) turn the electrolyte into a paste

Accepted Answer

The answer of The purpose of manganese dioxide and powdered...

Question 14

Silver-oxide cells and mercury cells offer the following advantage/advantages:&#10;A) high capacity in comparison with their size&#10;B) long shelf life&#10;C) are small enough to be used in watches, hearing aids, etc.&#10;D) each of the above

Accepted Answer

The answer of Silver-oxide cells and mercury cells offer the...

Question 15

A fully-charged lead-acid cell comprises electrodes of __________ and __________, and an electrolyte of __________.&#10;A) lead dioxide, metallic lead, dilute sulfuric acid&#10;B) lead sulfate, lead peroxide, dilute sulfuric acid&#10;C) lead sulfate, metallic lead, dilute sulfuric acid&#10;D) lead dioxide, metallic lead , concentrated sulfuric acid

Accepted Answer

The answer of A fully-charged lead-acid cell comprises electrodes of...

Question 16

The state of charge of a lead-acid cell may be determined by measuring its&#10;A) voltage&#10;B) current&#10;C) relative density&#10;D) temperature

Accepted Answer

The answer of The state of charge of a lead-acid...

Question 17

When a lead-acid cell de-energizes, both electrodes undergo a chemical reaction, with each changing to&#10;A) metallic lead&#10;B) lead dioxide&#10;C) lead peroxide&#10;D) lead sulfate

Accepted Answer

The answer of When a lead-acid cell de-energizes, both electrodes...

Question 18

As a lead-acid cell de-energizes, its relative density&#10;A) remains approximately constant&#10;B) increases towards 1.27&#10;C) falls towards 1.17&#10;D) increases towards 1.84.

Accepted Answer

The answer of As a lead-acid cell de-energizes, its relative...

Question 19

The device used to measure a lead-acid cell's relative density is called a&#10;A) hydrometer&#10;B) hygrometer&#10;C) densiometer&#10;D) calorimeter

Accepted Answer

The answer of The device used to measure a lead-acid...

Question 20

Memory effect' and 'voltage depression' are two drawbacks associated with&#10;A) lead-acid cells&#10;B) nickel-cadmium cells&#10;C) lithium-ion cells&#10;D) alkaline cells

Accepted Answer

The answer of Memory effect' and 'voltage depression' are two...

Question 21

The major advantages associated with lithium-ion cells are&#10;A) high capacity/weight ratio&#10;B) no 'memory effect' or 'voltage depression' problems&#10;C) capable of large number of energizing/de-energizing cycles&#10;D) all of the above

Accepted Answer

The answer of The major advantages associated with lithium-ion cells...

Question 22

The legislation which deals with the responsible disposal of used cells and batteries is the&#10;A) Electricity Supply Regulations&#10;B) Health and Safety at Work Regulations&#10;C) Waste Electronic and Electrical Equipment Directive&#10;D) Electricity at Work Act

Accepted Answer

The answer of The legislation which deals with the responsible...

Question 23

When three identical cells are connected in series, the resulting e.m.f. is __________ that of one cell&#10;A) one-third&#10;B) the same as&#10;C) three times

Accepted Answer

The answer of When three identical cells are connected in...

Question 24

When three identical cells are connected in series, the resulting current capacity is __________ that of one cell&#10;A) one-third&#10;B) the same as&#10;C) three times

Accepted Answer

The answer of When three identical cells are connected in...

Question 25

When three identical cells are connected in parallel, the resulting e.m.f. is __________ times that of one cell&#10;A) one-third&#10;B) the same as&#10;C) three times

Accepted Answer

The answer of When three identical cells are connected in...

Question 26

When three identical cells are connected in parallel, the resulting current capacity is __________ times that of one cell&#10;A) one-third&#10;B) the same as&#10;C) three times

Accepted Answer

The answer of When three identical cells are connected in...

Question 27

When connecting cells in series or parallel to create a battery,&#10;A) they should all be of the same type&#10;B) they should all be of the same brand&#10;C) their capacities may vary&#10;D) they must all be disposable types

Accepted Answer

The answer of When connecting cells in series or parallel...

Deck 9: Cells and Batteries