Module 4: Batteries and Balance

Question 1

What does an electric cell convert and what are the components? How does electricity flow in an electric cell?

Answer 1

An electric cell converts chemical energy into electrical energy.

Question 2

What are the components of a simple electric cell?

Answer 2

Question 3

Differentiate between electric current and voltage.

Answer 3

Electric current is the flow of electricity, measured
in amperes (A).
Voltage is the force that pushes on the current, measured in Volts (V)

Question 4

What is energy density, and how is it measured?

Answer 4

Energy density, or specific energy, measures how much energy a battery stores per unit mass. It’s measured in joules per kilogram (J/kg).

Question 5

What are primary cells?

Answer 5

Primary cells are non-rechargeable and include dry cells, alkaline dry cells, and mercury cells. They are used for their portability, cost-effectiveness, and sometimes higher current capabilities. hearing aids, watches, flashlights

Question 6

What are secondary cells?

Answer 6

Secondary cells are rechargeable. They include Ni–Cd cells and lead–acid batteries, used in vehicles, power tools, and portable electronics, providing large currents and reliability. all vehicles, laptops

Question 7

What are fuel cells, and what makes them unique?

Answer 7

Fuel cells generate electricity from continuously supplied fuel, offering high efficiency, lightweight designs, and environmental benefits. They are used in vehicles, space shuttles, and are being explored for electric cars.

Question 8

Write an empirical description for voltaic cell

Answer 8

A device that converts chemical energy into electrical energy by reacting two different metals with an electrolyte

Question 9

Write an empirical description for half cell

Answer 9

One part of a voltaic cell that contains one electrode in a electrolyte solution

Question 10

Write an empirical description for porous boundary

Answer 10

A barrier that allows for the flow of ions but prevents the mixing of the different substances

Question 11

Write an empirical description for salt bridge

Answer 11

A tube filed with an electrolyte solution that
connects the two half cells and allows ions to flow

Question 12

Write an empirical description for electrolyte

Answer 12

A substance that contains ions and conduct electrolyte

Question 13

Write an empirical description for external circuit

Answer 13

The external path where electrons flow from the anode
to the cathode

Question 14

Write an empirical description for inert electrode

Answer 14

A conductor that does not participate in the chemical reactions (sometimes graphite)

Question 15

Complete the following, which shows how the cathode and the anode in a voltaic cell differ. Place check marks in the appropriate boxes.

Answer 15

Question 16

Answer 16

Question 17

Complete the following tables. Use the diagram of the cell shown on p.44 of your coil booklet as a model of what your cell diagram should look like. Be sure to include the direction of electron movement and the direction of ion movement in each diagram.

Answer 17

Question 18

Complete the following tables. Use the diagram of the cell shown on p.44 of your coil booklet as a model of what your cell diagram should look like. Be sure to include the direction of electron movement and the direction of ion movement in each diagram.

Answer 18

Question 19

Answer 19

Question 20

Refer to the redox table in Appendix I, to represent the cell using the standard cell notation (listing the anode first). Identify the cathode and anode and calculate the standard cell potential without writing half- reaction equations.
copper–lead standard cell

Answer 20

Question 21

Refer to the redox table in Appendix I, to represent the cell using the standard cell notation (listing the anode first). Identify the cathode and anode and calculate the standard cell potential without writing half- reaction equations.
zinc–nickel standard cell

Answer 21

Question 22

Refer to the redox table in Appendix I, to represent the cell using the standard cell notation (listing the anode first). Identify the cathode and anode and calculate the standard cell potential without writing half- reaction equations.
iron(III)–hydrogen standard cell

Answer 22

Question 23

Answer 23

Question 24

Answer 24

Question 25

Define disproportionation

Answer 25

When one substance reacts with itself to make two different substances, redox reaction where an entity undergoes both oxidation and reduction

Question 26

Answer 26

Question 27

What is electrolysis?

Answer 27

Electrolysis is the flow of electrical current in a conducting solution or molten liquid that causes chemical changes. The conducting liquid, known as an electrolyte, contains free-moving ions.

Question 28

CNE APEs? CATs have PAWS

Answer 28

cathode, negative, electrolysis. Anode, positive, electrolysis. Cations are positive

Question 29

Describe the relationship of science and technology in the area of electrolysis. Include at least 2 examples in your description.

Answer 29

Question 30

Electron Measurement:

Answer 30

Electrons are measured indirectly through the mass of substances converted to chemical amounts.

Question 31

Charge Calculation:

Answer 31

• Charge (Q) in coulombs = Current (I) in amperes × Time (t) in seconds. Q=It
• One coulomb (C) is the quantity of charge transferred by a current of one ampere (A) during a time of one second
• Example: Charge transferred in a Hall–Héroult cell producing aluminium with 300 kA over 24 hours is calculated as 2.6 x 10¹⁰C

Question 32

Answer 32

Question 33

Procedure for Half-Cell Stoichiometry

Answer 33

1. Write the balanced equation for the half-cell reaction of the substance produced or consumed. List the measurements and conversion factors for the given and required entities.
2. Convert the given measurements to an amount in moles by using the appropriate conversion factor (M, c, F).
3. Calculate the amount of the required substance by using the mole ratio from the half-reaction equation.
4. Convert the calculated amount to the final quantity by using the appropriate conversion factor (M, c, F).

Question 34

A current of 0.5 amps flows in a circuit. How much charge passes through a point in the circuit in 2 minutes?

Answer 34

Question 35

An electroplating cell operates for 75 minutes with a current of 2.75 amps. Calculate the amount, in moles, of electrons transferred.

Answer 35

Question 36

Answer 36

Question 37

Answer 37

Question 38

Answer 38

Question 39

What is electroplating?

Answer 39

Electroplating is the process of coating an object with a thin layer of metal by depositing it at the cathode of an electrolytic cell, enhancing appearance and corrosion resistance,

Question 40

Answer 40

Question 41

Answer 41

Question 42

Which of the following actions will NOT minimize the corrosion of iron?
a. covering iron objects with a plastic coating
b. attaching pieces of copper to iron objects
c. passing electric currents into iron objects
d. electroplating iron objects with zinc

Answer 42

b

Question 43

Which of the following occurs when a piece of copper metal is placed in a solution of
HCl(aq)?
a. a spontaneous reaction with a positive E°net
b. a spontaneous reaction with a negative E°net
c. a nonspontaneous reaction with a positive E°net
d. a nonspontaneous reaction with a negative E°net

Answer 43

d

Question 44

Answer 44

0.26

Question 45

Answer 45

d

Question 46

Answer 46

c

Question 47

Answer 47

d

Question 48

Answer 48

d

Question 49

Answer 49

6. 0.80
7. 2357

Question 50

Answer 50

c