Reaction Rate Experiments
Today I will:

Understand the collision theory of chemical
reactions and how this relates to reaction rates.
I will know I have been successful if I can:




Use collision theory to explain changes in reaction
rates
Design and carry out an experiment to observes a
cause of changes in reaction rate.
Describe the steps in a chemical reaction using collision
theory.
What conditions must be met for a chemical reaction to
occur?
Kick start
Demonstration: glowsticks
1. Describe what you observe.
2. Use collision theory to explain your
observations
Demonstration: Elephant toothpaste
Hydrogen peroxide (H2O2) decomposes slowly into
water and oxygen. Potassium iodide can be added to
speed up the reaction.
1. Describe what you observe.
2. Write the chemical equation for this reaction.
3. Explain the role that potassium iodide plays in
this reaction.
Demonstration: Combustible flour
1. Describe what you observe.
2. Use collision theory to explain your
observations
Your group is to choose ONE of the reactions below which
explore factors which affect reaction rate.
You will plan and conduct an experiment based on the reaction
and supplied materials. Use the experimental template for your
planning and reporting.
A. Temperature and Reaction Rate
Aim
To investigate the effect of temperature on the rate of a
reaction
Materials
 3 Alka-Seltzer tablets
 Water at 3 different temperatures: cold (iced), room
temp and warm (approx. 40°C)
 Electric kettle
 3 x 250mL beakers
 Stopwatch
 Thermometer
 Marker pen
 100mL Measure cylinder
B. Surface Area and Reaction Rate
Aim
To investigate the effect of increasing the surface area on the
rate of reaction
Materials
 3 x Alka-Seltzer tablets
 Water
 3 x 100mL beakers
 Mortar and pestle
 50mL Measuring cylinder
 Stopwatch
C. Concentration and Reaction Rate
Aim
To investigate the effect of increasing the surface area on the
rate of reaction
Materials
 30g marble chips (calcium carbonate)
 Hydrochloric acid dropper bottles of 3 different
concentrations (0.1M, 1.0M, 2.0M)
 Measuring cylinder 25mL
 Conical flask small
 Cotton wool to plug mouth of flask
 Balance
 Stopwatch
Write up your experimental report using this scaffold:
Introduction
Aim
Variables
Independent variable:
Dependent variable:
Controlled variables:
Hypothesis
If....then....
Materials
Method
Risk
Assessment
Results
Discussion
Conclusion
Risk (Chemical
or equipment)
Injury (what
could go
wrong)
Prevention
(how to stay
safe)