P- Kinetics (P2) Flashcards
What is the collision theory?
Reactions can only occur when collisions take place
between particles having sufficient energy (Ea)
What are the conditions for collisions to happen?
- reacting particles collide w/ energy >= Ea
- collide at correct orientation
What is the effect of increasing temperature on collision frequency and energy?
- freq: ↑ ∵ ke↑
- ↑ ∵ faster
What does the area under the Maxwell-Boltzmann distribution graph represent?
total no. of particles
Why does the Maxwell-Boltzmann distribution graph always start at the origin?
zero particles have zero energy
?
Why does the Maxwell-Boltzmann distribution graph always start at the origin?
zero particles have zero energy
?
What does the peak of the Maxwell-Boltzmann distribution graph represent?
Emp- most probable energy
What is the effect of increasing temperature to the Maxwell-Boltzmann distribution curve?
- shifts to right
- ↑ proportion of particles have ke > Ea
What is a catalyst?
- a substance that increases the rate of a
chemical reaction -
without being changed in chemical
composition or amount
– provides an alternative reaction route of ↓Ea
Why does the Maxwell-Boltzmann distribution curve never touch the x-axis?
- poss for molecules to have any given energy (x max)
What happens to the Emp when a catalyst is used?
- ↑
- area under curve must stay the same
- ∴ ↑ molecules must have Emp
What happens to Ea when temp of a gas changes?
stays the same
What happens to Emp when temp decreases?
- decreases
- ∵ area under curve must be the same
What happens to number of reacting particles as Ea is decreased by a catalyst?
- doubles
- Ea moves to the left ∴ bigger area under the graph > Ea
What happens to the Emp when number of molecules increases?
x change
