Topic 9 Kinetics Flashcards
What is required for a reaction to occur
Particles collide with sufficient energy (>= activation energy) and with the right orientation
What is rate of reaction
Change of concentration or amount of substance per unit time
What do Maxwell Boltzmann distributions show
Energy in gas particles in a system
What 4 things happen to a Maxwell B distribution when temp increases
- Curve moves right
- Peak is lower
- Area stays the same
- Area below the curve past activation energy increases
What 5 things affect rate
- Conc
- Temp
- Surface area
- Pressure
- Presence of a catalyst
What is the difference between homogeneous and heterogeneous catalysts
Homo - same phase
Hetero - different phase
How do heterogeneous catalysts work
Reactants adsorb onto the surface of the solid catalyst. Radicals form as bonds are weaker and then radicals react to form new particles. New molecules desorb from the surface
How do homogeneous catalysts work?
They provide alternative multi step reaction route with lower total activation energy.
How are homogeneous catalyst energy profile diagrams different
They have 2 activation energies
3 reasons to use a catalyst in industry
- lower temperature less money of fuel and less environmental impact
- speed up reaction - time is money
- change properties of a product
2 environmental reasons to use a catalyst
- Lower temp and pressure required reduces waste
- Catalyst reactions may have better atomic economy so less waste is created
3 ways to measure rate
- Time to form ppt
- Mass loss over time
- Volume of gas collected over time
