Chapter 16 · Oxidation and Reduction
16.1The End of the Internal Combustion Engine?
7 min · two checks
Predict
What do a fuel cell and a battery have in common with a campfire?
The idea
- Connect combustion and batteries as electron-transfer reactions.
- Say what makes a battery different from a fire.
A gasoline engine and a hydrogen fuel cell both oxidize a fuel and reduce oxygen. In the engine the electrons move directly between molecules and the energy leaves mostly as heat, which is then partly turned into motion. In a fuel cell or a battery the electrons are forced through an external circuit first. Same chemistry family, different plumbing, and much more of the energy can become electricity.
This chapter names that electron transfer precisely, assigns oxidation states so you can see it even when no element is obvious, balances the equations, and then looks at the devices: batteries, electrolysis cells, and the slow redox disaster called corrosion.
Keep these
- Redox is electron transfer.
- Batteries and fuel cells send the electrons through a wire.
- Combustion is redox that mostly produces heat.