Unit 3: Equilibrium Flashcards
dynamic equilibrium
when opposing changes are occuring simultaneously at the same rate
- exists when the rate of the forward rection is equal to the rate of the reverse reaction
forward reaction
read left to right in a chemical reaction. while reverse is read right to left
conditions of all equilibrium systems
- equilibrium is achieved in a reversible process when the rates of opposing changes are equal
- the system is closed
- the observable (macroscopic) properties of the system are constant though microscropic changes are taking place
examples of chemical equilibrium systems
solubility
phase
chemical reaction
solubility equilibrium
- dynamic equilirium in a close system between a solute and a solvent of a saturated solution
- rates of dissolving equals rate of cryslizqation
saturated solution
one where the solvent has the maximum amount of solute issolved per unit volume
phase equilibrium
between different physical states of a pure substance in a closed system
- rates of freezing equals rate of melting H2O(l) -> h2O(g) t=100degrees
- rate of condensation equal rate of evaporation
chemical reaction equilibrium
between reactants and products of a chemical rection in a closed system
effective collsions between reactants to form products (forward reaction) equals the effective collisions between products to forms (reverse reaction)
percent reaction
actual product yield at equilibrium/quantitative theoretical yield(stoichiometry) X100
A system at equilibrium never
achieves completion , but rather there are always both reactants and products in the reaction mixture.
what is the equilbirum constant used as
a quantitative measure to determine the amount of reactants and products present at equilibrium for a given chemical system
is Keq temp dependant
YES
kreverse
1/keqforward
k»1
A higher [ ]+ of products and relatively low [ ]+ of reactants thus the eqbm favours the product side
k=1
[ ] + of reactants and products is approx equal thus the eqbm does not favour one side over the other
k«1
A higher [ ]+ of reactant and relatively low [ ]+ of products thus the eqbm favours the reactant side
what does favous mean
the side of equation has higher numbers of moles and higher concentration than the other
If keq is 1.0x10^10
has effectively gone to completion
if keq is 1.0X10^-10
essentialy incomplete
reaction quotient(Q)
concentration of products/ concentration of reactants
ICE
initial concentration
change in concentration
equilibrium concentration
