Kinetics Flashcards
Collision theory
Particles must collide with enough energy and have correct orientation for reaction to occur
Define rate of reaction
• change in concentration in a given time
What happens when a graph levels off
• Rate is zero
• no more collision possible between molecules
~ reactant used up
How to increase rate of reaction
• Increase concentration
~ more particles in given volume
• Increase Pressure
~ more particles in given volume
• increase Temp
~ more molecules have enough energy for successful collisions
• Catalyst
~ more molecules have enough energy to undergo successful collisions
Describe trend in rate curve
• Constant (linear)
~ at its fastest as greater frequency of successful collisions
• Rate decreases
~ reactants getting used up so less molecules to react with in given volume
• No rate of reaction—> plateaus
~ reactant molecules with enough energy completely used up
MB Distribution
Why does curve go through origin
All particles have energy
Where and what is most probable energy
• At peak
• particles most likely to have that amount of energy
Define activation energy
Min energy required for reaction to take place
Define catalyst
Speeds up reaction
How to catalyst work
•Provides alternative reaction route
• Lower Ae
Why may some molecules have low energy
• Collisions cause some molecules to slow down or lose energy
Change in temp in equilibrium
• Increase temp
~ System decrease temp
~ shifts to Endo
• Decrease temp
~ system increases temp
~ shifts to Exo
Effect of catalyst on equilibrium
• Invreases rate of forwards and backwards reactions equally
• no effect on position of equilibrium
• increase rate attainment of equilibrium
Effect of high pressure on cost and safety
Cost more
Need equipment to hold pressure
Higher risk of explosion
Safety decreases
