Kinetics Flashcards
Instantaneous Rate of Reaction
the tangent of the curve (looking at the slope of the line)
Average Rate of Reaction
the change of concentration over change in time of a reactant or product
If a reactant decreases…
its a negative rate of reaction
If a product increases…
its a positive rate of reaction
Collision Theory
in order to react, there has to be enough energy that is more than the activation rate, and a correct orientation
In order to create products….
The activated complex needs to be reached and in order to reach the activated complex, you need sufficient enough energy, or activation rate.
Factors that can affect rate
Temperature Pressure Concentration Surface Area Catalyst
Affect of Temperature
- proportional to kinetic energy which means that an increase in temperature causes more particles to have energy greater than the activation energy
Affect of Pressure
If particles are closer together, there is a greater chance of collision (only works on gas)
Affect of Concentration
More particles makes more collisions because there is more to react with
Affect of Surface Area
More exposure of particles in order to collide.
i.e. crushing a solid to expose area
(only with solids)
Affect of a Catalyst
provides an alternative reaction pathway with a lower activation energy
Maxwelll-Boltzman Distribution
an asymmetric bell curve that is a comparison with the number of particles to the amount of energy they have
Factors that affect the Maxwell Boltzman Distribution graph
Catalyst: less activation energy
Temperature: reduces/increases the area under the curve
Rate expressions
Shows what components of a reaction are being used to find the rate
General Form of rate expression
rate=k[A]^x[B]^y
Order
describes the degree by which changing concentration will change the rate
- lower order = less impact
Zero Order
No effect on the concentration
Ex: [2A]^0=Rate
First Order
any change to the concentration equals the change to the rate
Ex: [2A]^1=2Rate
Second Order
change to the concentration is change squared to the rate
Ex: [3A]^2=9Rate
Third Order
change to the concentration is change cubed to the rate
Overall Order
found by the sum of all exponents
Which value is the exponent/order?
The COEFFICIENT of the reactant/product becomes the exponent or order
To plug and solve a rate expression
- Find order of A
- Find order of B
- Put it together
- Solve for K
