Topic 8 – Chemical reactions
involving oxygen
Science 9 - Chemistry
Learning Target
1. Describe combustion, corrosion and other
reactions involving oxygen
Combustion
 Combustion is the highly exothermic
combination of a substance with oxygen.
Combustion requires heat, oxygen, and fuel.
Combustion
Oxygen reacts with a fuel source to
produce water vapor, carbon dioxide
gas and heat energy
Ex. Fire, explosion
Combustion: chemical equation
 CH4(g) + 2 O2(g)  CO2(g)+ 2 H2O (g)
 Methane + oxygen  carbon dioxide + water
Corrosion
Corrosion is a slow chemical change that
occurs when oxygen in air reacts with
metal
Ex. Rust
Corrosion: chemical equation
Rust:
Fe(s) + O2(g)  Fe2O3(s)
Iron + oxygen  iron oxide
How do we protect against rust?
 Galvanizing – Coating metals with thin
layers of zinc
– Zinc takes longer to rust than most metals!
 Painting
 Sacrificial metal
Guitar strings & bridges
 https://www.youtube.com/watch?v=GX6WKI
KGSkg coated guitar strings
 https://www.youtube.com/watch?v=yVQn1D
YmiXE (War on Corrosion)
3. CELLULAR RESPIRATION – chemical
reaction that takes place in your body
cells.
C6H12O6 + O2  CO2 + H2O + energy
Extra
 Products of combustion demo
https://www.youtube.com/watch?v=-Y2oK08CUc