C8 Reaction Kinetics Flashcards
(18 cards)
rate of reaciton
change in amount of reactants/products per unit time
graph of amount of product vs. time
visualise
graph of amount of reactant vs. time
visualise
average rate of reaction formula
average rate of reaction = total amount of product/total time taken
frequency of collision
frequency of collision = rate of collisions between the particles in the given volume per unit time
factors affecting frequency of collisions
- conc of solution
- temp of reaction mixture
- pressure of gas
- surface area of solid particles
effective collisions
collisions that produce chemical reactions
non-effective collisions
collisions that do not produce chemical reaction
requirements for effective collisions
- reacting particles collide with energy equal or greater than activation energy –> so a chemical reaction is produced
- collisions must be in the correct orientation
how does conc of solution and pressure of gas affect rate of reaction?
concentrated solution and high pressure causes there to be more particles per unit volume, so frequency of collisions between reacting particles increases, hence frequency of effective collisions between reacting particles increases, rate of reaction increases.
at constant temp, increasing conc and pressure of gas DOES NOT
does not increase KE of particles
does not alter activation energy of reaction
activation energy
minimum energy required for a collision to be effective
how does temperature affect Boltzmann distribution?
when temp increases, distribution shifts to the right. area of particles with energy equal or higher than activation energy increases, frequency of effective collisions increases, rate of reaction increases.
catalyst
a substance that increases the rate of reaction and remain chemically unchanged at the end of reaction
what does a catalyst do?
- provides an alternative pathway with lower activation energy
- more particles now have energy equal or higher than activation energy
- frequency of effective collisions increases and rate of reaction increases
homogeneous catalyst
catalyst in the same phase as the reactants
heterogeneous catalyst
catalyst in a different phase as the reactants
what does catalyst do to a Boltzmann distribution?
lowers the activation energy (DOES NOT affect shape of Boltzmann distribution)
