Maxwell Boltzmann Distribution and rate curves Flashcards
What do Maxwell Boltzmann distribution curves show?
how energy is distributed amongst gas particles
Why does the curve go through the origin?
as no particle has zero energy
What is the total area under the curve?
the total number of molecules
What goes on the x and y axis?
number of particles- y axis
kinetic energy- x axis
What is N.m.p?
number of particles with the most probable energy
What is E.m.p and where is it on the graph?
most probable energy, marked on x axis at the highest point of the curve
What is E.mean, where is it in relation to E.m,p?
the mean energy of the particles, and is just after the E.m.p
What is the shaded area of the graph right at the very end?
the Ea (activation energy)
What happens to the shaded area of particles with Ea when a catalyst is used?
the line moves back the graph, showing more particles have Ea
How does the shape of the curve change when there is a lower temperature?
the curve peaks higher and earlier, but comes down more steeply and to a lower point
Why does the shape of the curve change when there is a lower temperature?
at lower temperature there are fewer higher energy particles and more lower energy particles, so fewer particles have activation energy above the activation energy, so fewer successful collisions hence the slower the rate. lower temp= lower E.m.p
How does the shape of the curve change when there is a higher temperature?
the curve peaks lower and later, but comes down less steeply and to a higher point
Why does the shape of the curve change when there is a higher temperature?
at higher temperature there are more higher energy particles and fewer lower energy particles, and at higher temperature there are more particles with energy above the activation energy so more successful collisions hence the faster rate. higher temp= higher E.m.p
How do you calculate rate? (mol dm-3 s-1)
change in conc / change in time
Why is rate fastest at the start of a reaction?
more particles per unit volume, so most frequent successful collisions per second at the start
