kinetics Flashcards
What must particles collide with for a reaction to occur?
- sufficient energy to overcome the activation energy
- correct orientation (Stenc effect)
What are the 5 ways of increasing the rate of reaction?
- temperature (increases kinetic energy of molecules)
- pressure (increases number of gaseous molecules in a given volume)
- concentration (increases the number of molecules in a given volume)
- surface area (increases the area over which a reaction can occur)
- catalyst (lowers the activation energy by providing an alternate pathway for a reaction)
What does the area under the maxwell boltzmann distribution represent?
total number of particles
What does the area to the right of activation energy in the maxwell boltzmann distribution represent?
corresponds to number of molecules with sufficient energy to overcome energy barrier + react
Why does the curve start at origin?
no particles have 0 energy
What is greater average energy or most probable?
average energy is slightly grater than most probable energy
What happens to the Maxwell Boltzmann distribution if temperature is increased?
- area under the curve stays the same
- curve gets broader and flatter due to a greater spread of values
- shifts to higher energies/velocities
What happens to the Maxwell Boltzmann distribution if temperature is decreased?
- area under the curve stays the same
- curve gets narrower/more pointed due to smaller spread of values
- shifts to lower energies/velocities
What happens to the Maxwell Boltzmann distribution if a catalyst is added?
lowers the activation energy by providing an alternative pathway for a reaction
lowering the activation energy results in more energy under the graph after Ea because more molecules have enough energy to react
What is an advantage of catalysts?
cheaper to speed up a reaction using a catalyst rather than higher temperature or pressure because reactions take place at lower temperatures which save energy and reduce CO2 output
What are the features of catalysts?
not used up in the reaction
remain chemically unchanged after a reaction has taken place