Chemistry kinetics Flashcards
What must happen for a reaction to occur between molecules of two different gasses?
1) They have to have enough activation energy.
2) they have to be in the correct orientation.
3) they have to collide.
- they wont react if they are like the above
What are the factors that affect the rate of reaction.
1) increase in temperature.
2) increase in the concentration of a solution
3) increase in the pressure of a gas.
4) increase in the surface area of a solid.
5) using a catalyst.
how does increasing the temperature affect rate of reaction?
higher the temperature the more kinetic energy being created leading to more particles with the activation energy which increases the Successful collision frequency.
how does increasing the concentration of a solution affect rate of reaction?
more particles would be in a volume. which leases to an increase in successful collision frequency.
there could be more solids in a smaller volume or less solids a larger volume.
how does increasing the pressure of a gas affect rate of reaction?
this increases the frequency of successful collisions.
decrease the volume or more particles in the same volume.
how does increasing the surface area of a solid affect rate of reaction?
higher surface area to volume ratio. which means more collisions which increases the frequency of successful collisions.
how does using a catalyst affect rate of reaction?
it lowers the activation energy by providing an alternative pathway.
speeds up a reaction without being used up.
What is a Maxwell-Boltzmann distribution?
it is a theoretical model that has been developed to explain scientific observations.
describe the Maxwell-Boltzmann distribution curve.
1) The peak of the curve represents the most likely energy of any single molecule. mp (most probable)
2) the mean (average) energy of all the molecules is a bit to the right of the peak.
3) the curve start at (0,0) because no molecules have zero energy.
4) some molecules have more than the activation energy. these are the only ones that can react.
What is the area under the Maxwell-Boltzmann curve equal to?
the total number of molecules.
what happens if you increase the temperature of a gas?Max-Boltz curve
the peak would shift slightly forward and down.
the end of the curve would be higher than the one at a lover temperature. meaning it would have a greater activation energy.
What happens if you increase the concentration/pressure of a gas? Max-Bolts curve
the particles will on average be closer together. if they’re closer, the collisions are more frequent. if collisions are more frequent, theylll be more chances for particles to react.
- graph peak would be higher.
and end of th curve will be lower.
1)no particles have zero energy
2) few particles have very high energies.
3) most particles have intermediate energies
4) the average energy is not the same as the most probable energy.
