C6.2.10 Fuel Cells

Question 1

What is the electrolyte

Answer 1

Potassium hydroxide

Question 2

What are the electrodes made of

Answer 2

Carbon with a catalyst

Question 3

Where does hydrogen go

Answer 3

Anode

Question 4

Where does oxygen go

Answer 4

Cathode

Question 5

What’s odd about fuel cells

Answer 5

In electrolysis, the anode is usually positive, but in fuel cells, anodes are negative and the cathode positive.

Question 6

Equation for the negative electrode

Answer 6

H2 -> 2H(+) + 2e-

Question 7

Equation for the positive electrode

Answer 7

4H+ + O2 + 4e- -> 2H2O

Question 8

Overall reaction

Answer 8

2H2 + O2 -> 2H2O

Question 9

What kind of reaction is this?

Answer 9

Redox

Question 10

Advantages of fuel cells

Answer 10

Don’t generate pollutants

Really efficient

Question 11

Disadvantages of fuel cells

Answer 11

Quote expensive

Hydrogen is difficult to extract and store

Question 12

Making a chemical cell

Answer 12

1. Pour zinc Sulfate solution into a beaker and dip a zinc strip into it
2. Pour some copper(2) Sulfate solution into another beaker and dip the cotton strip into it.
3. Connect the two solutions using filter paper soaked using potassium nitrate solution
4. Connect a voltmeter to a metal strip to measure the pd.

Question 13

How does a chemical cell work

Answer 13

Exothermic reactions cause a pd or voltage between the 2 ends of a battery. When the cell is connected to an electrical circuit, current flows through the cell and the components of the circuit. This continues until one of the reactants is used up and the cell ‘goes flat’ and can’t provide a pd any longer.