Cmabridge Lower Secondary- Rate of reaction.pdf

Chemistry

1. Rate of Reactions

2. 8.1 Measuring the rate of reaction
The factors
that affect the
rate of reaction
Concentration
of the
reactants
Temperature
of the
reactants
Surface area
of the
particles/ size
of the
particles
Air
pressure
States of
the
reactants
Other
Reactivity
of the
reactants

3. How to measure the rate of a reaction

5. Observations
•There is an anomalous result at 90s.
•The chemical reaction has stopped after 270s.

6. Calculating the average rate of reactions

7. 8.2 Surface area and the rate of reactions
•When there are larger particles, there
is a lesser chance of getting contact
with the molecules of the reactants.
•This results less number of molecules
of the reactants to bond.
•When there are smaller particles
there is a higher chance of getting
contact with the molecules of the
reactants
•This results less possibility for the
molecules of the reactants to
collide on each other resulting less
products.

8. Experiment: Particle size and the rate of
reactions- Mg + H2SO4
Observation:

9. 8.3 Temperature and the rate of reaction
•In higher temperature particles
have higher kinetic energy.
•This results higher possibility
for the molecules of the
reactants to collide on each
other resulting more products.
•In lower temperature particles
have lower kinetic energy.
•This results less possibility for the
molecules of the reactants to
collide on each other resulting
less products.

10. Experiment: Temperature and the rate of
reactions- Sodium thiosulphate + HCl
Observation:

11. 8.4 Concentration and the rate of reaction
•In lower concentration, particles
have a lesser chance of colliding
with another particle.
•This results less possibility for the
molecules/ particles of the
reactants to collide on each other
resulting less products.
•In higher concentration, particles
have higher chance of colliding with
another particle.
•This results higher possibility for the
molecules/ particles of the reactants
to collide on each other resulting
more products.

12. Experiment: Concentration and the rate of
reactions- Marble chips + HCl

13. THE END