Kinetics Flashcards
What is activation energy?
the minimum energy particles need to collide with to cause a reaction
What is a catalyst?
a substance that increases rate of reaction without getting used up by offering an alternative route or mechanism with a lower activation energy
Draw a Maxwell Boltzmann distribution curve
GO GO GO
What is the area under a M-B curve?
Total number of particles
Why does M-B curve go through the origin?
No molecules with no energy
Why doesn’t M-B curve touch the x axis?
No maximum energy
What happens when temperature of a gas is increased?
- higher temp = molecules have wider range of energies than at lower temps
- More particles with energy greater than or equal to Ea
- Mean energy increases
What happens when temperature of a gas is decreased?
- Amount of particles at lower energies at lower energies increased
- less particles with energy greater than or equal to Ea
- mean energy decreases
What is always constant with temperature change?
total area as total number of particles is constant
What happens if you increase conc or pressure of a gas?
- increased = more particles per unit volume = more frequent successful collisions (no shape change so Emp is the same)
What happens if you double concentration?
Doubles no of particles and no of frequent successful collisions
What increases when conc or pressure is increased?
Bigger area as no of particles increases and so particles with energy greater than or equal to Ea increases
What happens to rate curve if temperature increased?
Rate increases so gradient is steeper but amount of product at the end is the same
What happens to rate curve if conc increased?
same initial rate (so same gradient) but amount of product will differ (double conc = double product)
What is rate of reaction?
The rate of reaction is defined as the change in concentration of a substance in unit time
Its usual unit is mol dm-3s-1
