Collision Theory Flashcards
Reactor rate must be controlled in industrial processes for 2 man reasons
Profit ( rate too low won’t make money)
Health & safety (rate too high can be dangerous)
Collision theory explains how particles react with each other, what 3 criteria’s must met in order for particles to react
•particles must collide with each other
•Particles must collide with sufficient energy in order for a reaction to occur
•particles must collide with favourable geometry
What is another term for sufficient energy
Activation energy
What is activation energy
The minimum amount of energy needed to react particles together and form an activate complex
How can activation energy be calculated
Subtracting potential energy of the reactants of the reactants from maximum potential energy in the reaction
A chemical always follows the same process no matter the type of reaction
Reactants—-> Activated complex—-> products
What is the actives complex
Unstable arrangement of atoms formed when the reactants bonds have been broken but products bonds haven’t been formed yet
Where is actives complex formed? During when?
Maximum of the potential energy barrier during a reaction
In all chemical reactions, chemical bonds are broken and new bonds are made
2 rulings
•energy is needed to break bonds
•energy is released to make bonds
What is enthalpy
Measure of chemical energy in a substance
What’s change in enthalpy
The energy difference between the products and the reactants
In an exothermic reaction the product energy is
Less than the reactants energy so energy is released to the surroundings
This is -sign before numerical value
In an endothermic the products energy is
Greater than that of the reactants so energy is absorbed from the surroundings
Positive sign
Forward reactions are exo
So what are reversed reactions
Endothermic
In short
Enthalpy changed= difference between p and r (P-R)
Activation energy= Maximum potential energy- reactant potential energy
Average rate measures what
Speed of a reaction over a period time
So what’s relative rate
The measure of speed at a specific point in the experiment
R= 1/T
