Chapter 4: 4.3 Electrolysis and Electrolytic Cells

Question 1

Define:

Electrolysis

Answer 1

A nonspontaneous chemical reaction is forced to occur by the application of electrical energy

Question 2

True or False:

A redox reaction that has a negative ΔG (positive E(cell)) will not occur spontaneously

Answer 2

False, it will occur spontaneously

Question 3

True or False:

A redox reaction that has a positive ΔG (negative E(cell)) will not occur spontaneously

Answer 3

True

Question 4

Where is electrolysis carried out in?

Answer 4

Electrolytic cell

Question 5

What is the minimum standard voltage required to force a nonspontaneous redox reaction to occur?

Answer 5

E(electrolysis) = -E(cell)

Question 6

Define:

Overpotential

Answer 6

The minimum aplied voltage necessary to force a nonspontaneous reaction has to be greater than the E(electrolysis)

Question 7

True or False:

The overpotential is not negligible

Answer 7

True, it has a major significance in industrial application

Question 8

What factors must be considered to determine the species that will be formed?

Answer 8

• Overpotential
• Non-standard concentrations
• Temperature

Question 9

True or False:

Most favourable species will be formed

Answer 9

True

Question 10

What are the products of the Chloro-Alkali Process?

Answer 10

• Chlorine gas
• Hydrogen gas
• Sodium hydroxide/lye

Question 11

Define:

Faraday’s Law

Answer 11

The number of moles of products reduced or oxidized by the passage of an electric current through an electrolytic cell is stoichiometrically equivalent to the number of moles of electrons supplied

Question 12

Using the Faraday constant, how can the absolute charge (Q) of n moles be calculated?

Answer 12

Q = n(e)F

Question 13

How is the equation for electric charge usually written (in terms of current and time)?

Answer 13

Q = It