Chemistry In Society Flashcards
(17 cards)
What processes must reactions rates be controlled by
An industrial processes
What happens is the rate is too low in the industrial processes
The process will not be economically viable
What happens is the rate is too high in the industrial processes
There will be a risk of explosion
What speeds up a reaction rates
Increase in temperature
Increase in concentration
Increase in pressure
Add a catalyst
Increase surface area/smaller particle size
What must happen for a reaction to take place
Particles must collide
The more _____ ,the faster the reaction
Collisions
What does low concentration show?
Low concentration shows few particles, few collisions mean low rate.
What does small particles/an decrease of the surface area show?
Big particles, smaller surface area, fewer collision, low rate
What does low pressure show?
Low pressure, lots of space between particles, fewer collisions, low rate of reaction
Do all collisions result in a reaction?
No, not all collisions result in a reaction
How do collisions to be successful and what 2 criteria must be met
Correct collision geometry
Particles must be activation energy (Ex)
What do catalyst provide
A catalyst provides an alternative reaction pathway with a lower activation energy
What does the enthalpy change
The energy difference between the products and the reactants.
The enthalpy change has a _________ value for exothermic reaction
Negative
The enthalpy change has a _________ value for endothermic reaction
Positive
What is the activation energy
It is the minimum energy required by colliding particles to form an activated complex and can be calculated from potential energy diagrams.
What is the activated complex
It is an unstable arrangement of atoms formed at the maximum of the potential energy barrier, during a reaction
