10 reaction rates and equilibrium Flashcards
absorption
process that occurs when a gas/liquid/solute is held to the surface of a solid
catalyst
substance that increases the rate of a chemical reaction without being used up in process.
provides alternative route for reaction with lower Ea
closed system
system isolated from surroundings
collision theory
two reacting particles must collide for a reaction to occur and must be in the correct orientation and have sufficient energy to overcome the Ea of the reaction
desorption
release of an absorbed substance from a surface
dynamic equilibrium
equilibrium that exists in a closed system when the rate of forward reaction is equal to rate of reverse reaction and concs don’t change
equilibrium constant, Kc
a measure of the position of equilibrium, indicates whether there are ,ore reactants or products in an equilibrium system
heterogenous catalyst
catalyst has a different physical state from the reactants
frequently reactants gases whilst catalyst solid
homogenous catalyst
catalyst and reactants are same physical state
frequently the aqueous or gaseous state
Le Chateliers principle
when a system in dynamic equilibrium is subjected to a external change the system readjusts itself to minimise the effect of change and to restore equilibrium
position of equilibrium
the relative quantities of reactants and products indicting the extent of a reversible reaction at equilibrium
rate of reaction
the change in conc of a reactant or a product in a given time
reversible reaction
a reaction that takes place in both forward and reverse directions
activation energy Ea
minimum energy required to start a reaction by the breaking of bonds
