3.2.2- Reaction Rates Flashcards
What must a reaction have to collide successful?
Energy greater than or equal to the activation energy, and a correct orientation
What is activation energy?
The minimum amount of energy required for two particles to react
What is the rate of reaction?
How fast reactants are being used up or products being formed
What is the effect of temperature on a reaction?
More collisions have energy greater than the activation energy so more successful collisions
What is the effect of concentration and pressure on a reaction?
There are more molecules in the same volume so collisions are more likely
What is the effect of surface area on a reaction?
Increases the number of exposed reactant particles, so there are more collisions
What is a catalyst?
A substance that increases the rate of reaction without being used up in the reaction by providing an alternative reaction path with a lower activation energy
Why are catalysts economically important?
They lower the energy costs, allow lower temperatures and pressures to be used, and can give a higher atom economy
What is a homogenous catalyst?
A catalyst in the same phase as the reaction
What is a heterogenous catalyst?
A catalyst in a different phase to the species in the reaction
Why do transition metals make good catalysts?
They have variable oxidation states
How does a solid catalyst work?
It adsorbs molecules to an active site on the surface of the catalyst, which increases the proximity of molecules and weakens the covalent bonds in the molecules
How does temperature shift a maxwell-boltzmann distribution?
It causes a shift to the right as a greater proportion of molecules have greater kinetic energy
How does a catalyst change the boltzmann distribution?
Causes a shift of activation energy to the left
How does a catalyst change the boltzmann distribution?
Causes a shift of activation energy to the left
