Reactivity 2.3.1 Dynamic Equilibrium

Dynamic Equilibrium

A reaction takes place at the same rate as the reverse reaction so no net change is observed

Two Equilibrium systems

physical and chemical systems

eg physical equilibrium

bromine= volatile liquid; liquid to gaseous through condensation and evaporation

explanation: rate of condensation increasing with increasing concentration of vapour as more vapour particles collide with the surface of the liquid - eventually rate of condensation is equal to the rate of evaporation

eg chemical equilibrium

reaction of dissociation between HI and H2/I2

just what youd think

equilibrium mixture

the result of a dynamic equilibrium

forward reaction

reaction from left to right

reverse reaction

reaction from right to left

equilibrium is dynamic

reaction has not stopped but forward and backward reaction are at the same rate. products and reactants get produced and destroyed at the same rate

equilibrium is achieved in a closed system

equilibrium is reached where both reactants and products can react and recombine with each other

at equilibrium there is no change in macroscopic properties

they dont change as they depend on the concentrations of the components of the mixture

macroscopic properties

such as colour, density (observable properties)

equilibrium can be reached from either direction

will result under the same conditions no matter if the reaction is started with all reactants, products or both.

difference between concentration being constant and equal

• constant eg always 1:3

• equal eg 2:2

equilibrium position

proportion of reactant to product

reaction where the mixture is predominantly products and a l’envers

“lies to the right” “lies to the left”