Reaction Kinetics Flashcards
(18 cards)
what is rate of rxn?
the speed at which the rxn takes place (mol dm^-3 s^-1 of reactant being used up
what is the formula for concentration using number of mols and volume?
C = n/V
what is the formula for number of mols
number of mols = mass ove molar mass
n=m/M
what is the formula for rate of reaction
rate of rxn = change in concentration (of reactants or products) over change in time
what is needed for two molocules to react?
they must have suffishent energy, correct oriontation and must collide with the nesisary activation energy
what is collision frequency? and how does it effect rate of rxn
how often molocules colide mesured in collisions per unit time. a higher collision frequency causes more effective collisions per unit time resulting in a greater rate of rxn
how does pressure effect rate of rxn (for gasses)?
less volume
on a [Product] / [reactant] VS time graph what is the gradiant
the gradeant is the rate of rxn
is the rate of rxn directly proportional to the [Reactants] or [Products]
yes
what is the Boltzmann distribution curve?
a graph that shows the distrobutions of energy at cirtain tempritures
e.g praticles with high/low energies
avg energy
energys of different particles
what is a catalyst?
a substance that lowers the activation energy required for particles to react in turn increasing the rate of reaction.
on the bolman distrobution curve what are the acees?
the y axis is number of molocules and the x axis is the kinetic energy
what does Ea represent on the boltman distrobution curve and what happens to all molocules after it
Ea represents the minimum activation energy required for a reaction, all molocules after this Ea have enough energy to react
how does a catalyst effect the boltzman distrobution curve?
squashes the curve and makes it longer therefore giving more molocules above the nesisary activation energy
difine catalysis
the proces in which the rate of rxn is increced due to adding a catlyst
what is a homo geanus catalyst?
a catalyst that is in the same phase as rectants (e.g. solid, liquid, gass)
what is a hetrogeanus catalyst?
a catalyst that is in a different phase to the reactants
at a base level what does a catalyst do?
increases the number of molecules with the necessary activation energy
