Chapter 12 Electrochemical Processes

Question 1

What are Galvanic cells?

Answer 1

Galvanic cells/ Electrochemical cells use a redox reaction to produce a voltage (potential difference or EMF) that results in an electric current.

Question 2

How do Galvanic/ Electrochemical cells achieve a redox reaction while maintaining separation of reagents?

Answer 2

• A galvanic cell uses two electrodes.
• One electrode is in contact with the oxidising agent and reduction occurs here.
• The other electrode is in contact with the reducing agent and oxidation occurs here.
• A redox reaction can only take place inside a galvanic cell when a metallic conductor connects the two electrodes.
• The conductor allows electrons to flow from the reducing agent to the oxidising agent.

Question 3

What is the purpose of a Salt Bridge?

Answer 3

It allows both positive and negative ions to move between the oxidising agent and reducing agent.

-The salt bridge makes contact with both the oxidising agent and reducing agent in the galvanic cell.

Question 4

List the essential components of all galvanic cell.

Answer 4

1. Anode
2. Cathode
3. Electrolyte
4. Salt Bridge
5. Oxidation half cell
6. Reduction half cell

Question 5

Role of Anode.

Answer 5

• Oxidation occurs here.

- This electrode makes contact with the reducing agent (reductant) and is labelled the negative (-) terminal.

Question 6

Role of Cathode.

Answer 6

• Reduction occurs here.

- This electrode makes contact with the oxidising agent (oxidant) and is labelled the positive (+) terminal.

Question 7

Role of Electrolyte.

Answer 7

• Electrodes are immersed in an electrolyte solution.

- Ions in the electrolyte conduct charge in the solution and might themselves become oxidised or reduced.

Question 8

Role of Salt Bridge.

Answer 8

• Contains a non reactive electrolyte solution.
• It prevents direct contact between the oxidising and reducing agents while permitting ions to flow through it.
• Anions flow through the salt bridge towards the anode while cations flow to the cathode.

Question 9

Role of Oxidation half cell.

Answer 9

• This is the part of the cell where oxidation occurs.

- It consists of the anode plus the surrounding electrolyte.

Question 10

Role of Reduction half cell.

Answer 10

• This is the part of the cell where reduction occurs.

- It consists of the cathode plus the surrounding electrolyte.