Topic 8 – Reaction Rate
Science 9 - Chemistry
Learning Target
1. Describe combustion, corrosion and other
reactions involving oxygen
Chemical Reactions involving oxygen
1. COMBUSTION - oxygen reacts with a
fuel source to produce water vapor,
carbon dioxide gas and heat energy
Ex. Fire, explosion
What products are produced in
combustion?
 CH4(g) + 2 O2(g)  CO2(g)+ 2 H2O (g)
 Methane + oxygen  carbon dioxide + water
2. CORROSION – slow chemical change
when oxygen in air reacts with metal
Ex. Rust
4 Fe(s) + 3 O2(g)  2 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
PBS Nova – Smart Bridges
 https://www.youtube.com/watch?v=8qcREJ
2NsOQ (SmartBridge)
 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
Learning Target
 Identify conditions that affect the rates of
reactions.
Factors Affecting Rates of
Chemical Reactions
REACTION RATE – the speed at which
reactants are converted to products during a
chemical reaction.
Factors Affecting Rates of
Chemical Reactions
 Many factors can affect chemical reactions
– How can you make water boil faster?
1. Changing Temperature
• Temp = reaction rate
• Temp = reaction rate
 2. Stirring the Reactants
 Adding movement energy and speed of
atoms / molecules = collisions between
atoms = reaction rate
3. Increasing Surface Area
surface area = reaction rate
Catalysts
4. Catalysts – A substance that
being changed itself
RR without
Ex. Enzyme (natural catalyst) – made by living things
 Enzymes in the human body
https://www.youtube.com/watch?v=myORD
WVzNhc
5. Changing Concentrations – number of
particles (atoms or molecules) per unit of
volume changes reaction rate
# of particles / unit of volume =
# of particles / unit of volume =
X mol/L acetic acid (aq)
vs.
.8 mol/L acetic acid (aq)
RR
RR
 Bozeman science
https://www.youtube.com/watch?v=6mAqX3
1RRJU
 Ted-Ed
https://www.youtube.com/watch?v=OttRV5y
kP7A