Chapter 14:Chemical Kinetics
Dr Grace Ngubeni
, Kinetics
• Kinetics is the study of how fast chemical reactions occur.
• Besides information about the speed at which reactions
occur, kinetics also sheds light on the reaction mechanism
(exactly how the reaction occurs).
• There are 4 important factors which affect rates of
reactions:
• Physical state
• Concentration
• Temperature
• Catalyst
• Goal: to understand chemical reactions at the molecular
level.
© 2012 Pearson Education, Inc.
, Factors affecting rate of reactions
1. Physical State of the Reactants
o For molecules to react, they must touch each other.
The molecules are NOT chemically altered.
o The more homogeneous the mixture of reactants,
the faster the molecules can react.
© 2012 Pearson Education, Inc.
, Physical State of the Reactants
Powder medicine Tablet Medicine
1. Large surface area
2. No disintegration step
3. Immediate availability
a medicine in the form of a fine powder dissolves in the stomach and
enters the blood more quickly than the same medicine in the form
of a tablet.
Dr Grace Ngubeni
, Kinetics
• Kinetics is the study of how fast chemical reactions occur.
• Besides information about the speed at which reactions
occur, kinetics also sheds light on the reaction mechanism
(exactly how the reaction occurs).
• There are 4 important factors which affect rates of
reactions:
• Physical state
• Concentration
• Temperature
• Catalyst
• Goal: to understand chemical reactions at the molecular
level.
© 2012 Pearson Education, Inc.
, Factors affecting rate of reactions
1. Physical State of the Reactants
o For molecules to react, they must touch each other.
The molecules are NOT chemically altered.
o The more homogeneous the mixture of reactants,
the faster the molecules can react.
© 2012 Pearson Education, Inc.
, Physical State of the Reactants
Powder medicine Tablet Medicine
1. Large surface area
2. No disintegration step
3. Immediate availability
a medicine in the form of a fine powder dissolves in the stomach and
enters the blood more quickly than the same medicine in the form
of a tablet.
