Chapter 10 Boltzmann distribution Flashcards
What does the Boltzmann distribution curve show?
The spread of molecular energies in a sample of gas molecules (some molecules have more energy and so move faster)
General trend described by the Boltzmann distribution curve?
Most molecules have close to the average energy so move close to the average speed, though some may have more or less energy than this
Where does the curve always begin and why
At the origin: No molecules ever have zero energy
What is the area under the boltzmann curve equal to
The total number of molecules in the sample
Why doe the curve never again meet the x axis after beginning
Because there is no max energy a molecule can have so there will never again be an amount of energy with zero molecules
What happens to the shape of the Boltzmann curve when a higher temperature is provided
The peak is lower and shifted to the right
Affect of increasing temp on energy of molecules
At a higher temp a greater proportion of molecules have an energy greater than or equal to the activation energy
Affect of increasing temp on frequency of collisions
Particles have higher Ek so move faster
Overall affect of increasing temp
Greater proportion of successful collisions
More frequent collisions
Increased RoR
What happens to the line showing activation energy on the Boltzmann curve when a catalyst is used
It shifts to the left, so there is a greater shaded region to it’s right (more molecules with energy greater than or equal to activation energy)
Label for x axis of Blotzmann curve
(Kinetic) energy
Label for y axis of Boltzmann curve
Number of molecules with a given energy
What is the most important/ greatest affect that increasing temp has
Greater proportion of molecules with an energy greater than the E sub a
