| Question | Answer |
| Non rechargeable/Primary | provides electrical energy until chemicals have reacted to extent that V fails |
| Rechargeable/Secondry | chemicals react
recharging reaction is reversed and chemicals are regenerated |
| Examples of secondry cell | Ni/Cadmium
Li ion/Li polymer (laptops) |
| Fuel Cells | external supplies fuel+oxidant
continual electrical supply as long as reactants supplied |
| Which terminal in the fuel cell provides electrons? | -ve terminal
(no recharging required) |
| What does a fuel cell required | electrolyte
fuel/oxidants |
| Where does the hydrogen come from for hydrogen cars? | H2g/hydrogen rich fuels
(methanol, natural gas, petrol) |
| How is the hydrogen generated? | Fuel reacted with water to produce hydrogen and CO2 |
| Why is methanol used as a fuel? | easier to store than a gas
generated from biomass
CO2 is produced |
| Advantages of Hydrogen | less CO2
less pollution/ air pollutants
greater efficiency/ fuel consumption |
| How is hydrogen stored | liquid under pressure
adsorbed
absorbed into lattice structure |
| Limitiations | Toxic chemicals in fuel cells
Fuel cells have a limited lifetime
Absorbers/adsorbers limited lifespan
Feasibility of storing a pressurised liquid
Large scale storage and transport (cost effective/infrastructure) |
| Hydrogen economy | hydrogen must be accepted as a fuel
problems with handling and maintanence
engergy carrier not energy source |
| What is a battery | more than one cell joined together |
| example of primary batteries | zinc-carbon
alakaline
lithium |
| Examples of secondary batteries | Li ion
lead-acid
nickel-cadmium |
| During the reverse reaction what happens to the products from the forward reaction | products stick to electrodes not dispearsed into the electrolyte |
