In S
[] of reactant(s) or product(s) decreased
· both reaction rates decrease
· reaction that increases concentration of removed substance
is favoured
Chemical equilibrium Le Chateliers Principle :
occurs when z reversible Catalyst is added
·
dynamic chemical equilibrium :
· define :
When an external stress (change, · both reaction rates increase by the same amount
processes are occuring simultaneously at the same rate concentration
In
,
temperature or
pressure
Idenoted with double half arrow ->> is applied to a system in chemical equl . E quilibrium Constant (Kc)
· open system both matter
and heat :
can enter and leave system librium
,
the equilibrium point will change in · KC depends on temperature only ,
If temperature changes
· closed system
:
only heat can escape/enter the system such a
way as to counteract stress KC will change .
endothermic
example N 0x(g) =
2NOz(g) It indicates to what extent the reactants have
changed
(AH)0))
:
= ·
becaus
effects of different disturbances on equilibrium :
into products by the time equilibrium is established
- refers to forward
reaction
Temperature increased :
· Must use concentrations at
equilibrium
rate of reaction
·
both reaction rates increase
1 .
e)aA + bB - c) + dD then kc = [A]
*
x[B]b
· endothermic reaction is favored (DH) 0
remember as Ke =
[products] (C) x [D]9
·
If forward reaction is endothermic KC increases
[reactants]
,
formed faster
being decreases
· If forward reaction is exothermic ,
KC
time · K 1 :
(products]< Creactants] ·
temperature decreased ↳ The higher the value of Ke the higher
Chemical closed system
the
yeild of the reaction
·
dynamic equilibrium : in a ,
both reaction rates decrease [reactants]
forward reaction
· 0 kc < 1 :
<products] <
the rate of the is equal to the rate
exothermic reaction is favored ↳ The lower the value of Kc the lower the yelld of the reaction
· ,
of the reverse reaction
o if forward reaction endothermic ; le decreases
Note :
When equilibrium is established the ,
amounts of note :
homogenous equilibrium
-
products and reactants in same phase
· If forward reaction exothermic ; KC increases
both reactants and products remain constant different
heterogenous equilibrium -
products and reactants in phases
pressure increased
NO c ·
both reaction rates increase
amount N204 · reaction that produces feler moles of
gas
(mol)
-
(determined by · is favoured
mole ratio
pressure decreased
time
·
both reaction rates decrease
· factors affecting dynamic chemical equilibrium , reaction that produces more moles of
the following factors can the favoured
external change rate
gas is
of reaction
↓ 2) of reactant (s) or product(s) increased
concentration (aq) and
(g)
- both reaction rates increase
temperature ·
-
pressure (g) · reaction that lowers (J of added substance is
(disturb equilibrium as they will
change rate of reaction) favoured
[] of reactant(s) or product(s) decreased
· both reaction rates decrease
· reaction that increases concentration of removed substance
is favoured
Chemical equilibrium Le Chateliers Principle :
occurs when z reversible Catalyst is added
·
dynamic chemical equilibrium :
· define :
When an external stress (change, · both reaction rates increase by the same amount
processes are occuring simultaneously at the same rate concentration
In
,
temperature or
pressure
Idenoted with double half arrow ->> is applied to a system in chemical equl . E quilibrium Constant (Kc)
· open system both matter
and heat :
can enter and leave system librium
,
the equilibrium point will change in · KC depends on temperature only ,
If temperature changes
· closed system
:
only heat can escape/enter the system such a
way as to counteract stress KC will change .
endothermic
example N 0x(g) =
2NOz(g) It indicates to what extent the reactants have
changed
(AH)0))
:
= ·
becaus
effects of different disturbances on equilibrium :
into products by the time equilibrium is established
- refers to forward
reaction
Temperature increased :
· Must use concentrations at
equilibrium
rate of reaction
·
both reaction rates increase
1 .
e)aA + bB - c) + dD then kc = [A]
*
x[B]b
· endothermic reaction is favored (DH) 0
remember as Ke =
[products] (C) x [D]9
·
If forward reaction is endothermic KC increases
[reactants]
,
formed faster
being decreases
· If forward reaction is exothermic ,
KC
time · K 1 :
(products]< Creactants] ·
temperature decreased ↳ The higher the value of Ke the higher
Chemical closed system
the
yeild of the reaction
·
dynamic equilibrium : in a ,
both reaction rates decrease [reactants]
forward reaction
· 0 kc < 1 :
<products] <
the rate of the is equal to the rate
exothermic reaction is favored ↳ The lower the value of Kc the lower the yelld of the reaction
· ,
of the reverse reaction
o if forward reaction endothermic ; le decreases
Note :
When equilibrium is established the ,
amounts of note :
homogenous equilibrium
-
products and reactants in same phase
· If forward reaction exothermic ; KC increases
both reactants and products remain constant different
heterogenous equilibrium -
products and reactants in phases
pressure increased
NO c ·
both reaction rates increase
amount N204 · reaction that produces feler moles of
gas
(mol)
-
(determined by · is favoured
mole ratio
pressure decreased
time
·
both reaction rates decrease
· factors affecting dynamic chemical equilibrium , reaction that produces more moles of
the following factors can the favoured
external change rate
gas is
of reaction
↓ 2) of reactant (s) or product(s) increased
concentration (aq) and
(g)
- both reaction rates increase
temperature ·
-
pressure (g) · reaction that lowers (J of added substance is
(disturb equilibrium as they will
change rate of reaction) favoured
