Electrode Potentials and Electrochemical Cells: Commercial Applications of Electrochemical Cells

Question 1

What kind of cells are there?

Answer 1

• Non-rechargeable

- Rechargeable

Question 2

What type of reactions take place in non-rechargeable cells?

Answer 2

• Irreversible

Question 3

What type of reactions take place in rechargeable cells?

Answer 3

• Reversible

Question 4

Where are lithium-ion cells used?

Answer 4

• Mobile phones

- Laptops

Question 5

What reactions occur in a lithium-ion cell?

Answer 5

• Cathode
- Li+ (aq) + CoO2 (s) + e- ⇌ Li+[CoO2]- (s)

• Anode
- Li (s) ⇌ Li+ (aq) + e-

Question 6

How are rechargeable cells recharged?

Answer 6

• Current is applied
• Forces electrons to move in opposite direction
• Causes reaction to reverse, recharging the cell

Question 7

What are fuel cells?

Answer 7

• Type of electrochemical cell that can generate an electrical current without needing to be recharged

Question 8

What reactions occur in an alkaline hydrogen-oxygen fuel cell?

Answer 8

• Cathode
- H2 (g) + 2OH- (aq) → 2H2O (l) + 2e-

• Anode
- O2 (g) + 2H2O (l) + 4e- → 4OH- (aq)

Question 9

What are the benefits of fuel cells?

Answer 9

• More efficient, convert more of their available energy into other energy stores
• Only waste product is water, so no toxic chemicals
• Don’t need to be recharged

Question 10

What are the cons of fuel cells?

Answer 10

• Need energy to produce supply of hydrogen
• E.g electrolysis of water may be generated with fossil fuels
• Hydrogen is highly flammable
• Hydrogen fuel infrastructure not widely available for hydrogen fuel for cars