Rate of Reaction
The change in concentration per unit time of either a reactant or
product
Rate = [products]tor Rate = [reactants]t
Collision Theory
A model that explains reaction rate as the result of particles
colliding with a certain minimum energy to form products
Rate of Reaction is directly proportional to:
1. Number of collisions per unit time
2. Fraction of collisions that are effective
More collisionsincreased reaction rate
Factors affecting the Rate of Reaction
Temperature
When temperature increasesaverage kinetic energy of particles
increases:
1. Particles move faster more collisions per unit time
2. Fraction of collisions that are effective increases (ave. Ek)
An increase in temperature therefore results in increased reaction
rate (number of effective collisions per unit time )
Concentration (solutions)
When concentration increases, there are more particles per unit
volumemore effective collisions per unit time
An increase in concentration therefore results in increased reaction
rate
Pressure (gases)
When pressure increases, molecules are closer togethermore
collisions will occur
An increase in pressure therefore results in an increased reaction
rate
Surface Area (solids)
A solid has a larger surface area when it is powdered
When surface area increases, there is more space for effective
collisions & the number of collisions per unit time increases
An increase in surface area therefore results in an increased
reaction rate