3.5 Kenetics Flashcards
What is rate?
The change in concentration of reactants or product per unit time
measure of how fast a reaction takes place
Explain collision theory
Particles must collide with enough energy at thee same orientation to react
What’s Activation Energy
the minimum amount of energy particles need to react
Factors affecting rate
- Concentration of solution
- Surface area of solid
- Pressure of gasses
- Temperature
- Catalyst
How does the concentration of solution affect rate?
higher the conc the faster the reaction
Particles are closer together so more succesfull collisions
How does the surface area of a solid affect rate?
the more pices a solid is broken into the surface area is larger
more particles exposed, more particles collide, more SC, faster rate
How does the pressure of gasses affect rate?
higher the presure - faster the reaction
particles closer together = more SC
How does the temperature affect rate?
higher the temp = faster the rate
more particles with more kenetic energy, move faster, more SC
How does the catalyst affect rate?
a substance which increases rate but is not used up
provides an alternative route, lowers Ea, more particles are equal to or above Ea - more succesfull collisions
Order of reaction
with respect to a given reactant is the power of reactants concentration in the experimentally determined rate step
Rate equation
is an expression to show how rate is related to concentration of individual reactants at a constant temperature
What letter is used to represent the rate constant
k
Zero Order
rate is unaffected by changes in the respective reactants concentration
First order
rate is directly proportional to the respective reactants concentration
