Producing electricity using Chemistry

Question 1

How does a cell go flat?

Answer 1

Batteries in portable devices are chemical cells - ex other mic reactions in the cell develop a p.d between two ends and when the cell is connected to an electrical circuit, a current flows through the cell and the components of the circuit ; continues until one of the reactants is used up and the cell then goes flat

Question 2

How to make a chemical cell?

Answer 2

Dip zinc strip into zinc sulfate solution
Dip copper strip into copper sulfate solution
Connect two using filter paper soaked with potassium nitrate
Connect a voltmeter to measure the p.d (electrolytes are zinc sulfate and copper sulfate)

Question 3

What is a fuel cell?

Answer 3

A fuel cell produces electricity through a chemical reaction between a duel and oxygen without combustion occurring

Question 4

Hydrogen and oxygen reaction

Answer 4

An exothermic reaction to produce water vapour

Question 5

How does a hydrogen oxygen fuel cell work?

Answer 5

1) Hydrogen molecules lose electrons to become hydrogen ions
2H2 (g) -> 4H+ (aq) + 4e-
Ions pass through proton exchange membrane to other side and electrons travel through external circuit to other side of fuel cell
2) Hydrogen ions combine with O2 and electrons at other side - H2O
4H+ (aq) + 4e- + O2(g) -> 2H20 (g)

Question 6

Comparison between battery and fuel cell

Answer 6

Fuel cell refuels much faster than battery
Fuel cell is more expensive for refuelling
Fuel cell emits less CO2
Fuel cell has a much lower mass of car